//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21693 SUBJECT: LIGO/Virgo G299232: Identification of a GW Compact Binary Coalescence Candidate DATE: 17/08/25 14:25:50 GMT FROM: Karelle Siellez at Georgia Inst of Tech The LIGO Scientific Collaboration and Virgo report: The MBTA CBC analysis (Adams et al. CQG 33, 175012, 2016) identified candidate G299232 during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2017-08-25 13:13:31 UTC (GPS time: 1187702035.9831). Data from Virgo (V1) were included in a followup analysis using the PyCBC toolkit (Nitz, et al. 2017, arXiv:1705.01513) and used to generate the localization given below. G299232 is a low-significance CBC candidate with a false alarm rate, As determined by the online analysis, of 1.68e-07 Hz, or about 5.3 per year, just within our threshold of 6 per year for announcing candidates. The event's properties can be found at this URL: https://gracedb.ligo.org/events/view/G299232 If the candidate is astrophysical in origin, it appears consistent with the merger of a black hole and a neutron star. For more details on the source classification, please consult this technical document: https://dcc.ligo.org/T1600571/public/main A rapid localization with distance information generated by the BAYESTAR pipeline (Singer et al. 2016, ApJL 829, 15) including information from H1, L1, and V1 is available and can be retrieved from the GraceDB event page: bayestar-HLV.fits.gz. The 50% credible region spans about 450 deg2 and the 90% region about 2040 deg2. The probability is concentrated in a pair of long, thin arcs that spread across both the northern and southern hemispheres, although the probability is concentrated in the northern hemisphere. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 339 +/-110 Mpc. Updates on our analysis of this event, including updated localizations will be sent as they become available. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21694 SUBJECT: LIGO/Virgo G299232: FOUND COINCIDENT IceCube neutrino observation DATE: 17/08/25 14:26:41 GMT FROM: Stefan Countryman at LIGO Scientific Collaboration I. Bartos, S. Countryman (Columbia), C. Finley (U Stockholm), E. Blaufuss (U Maryland), R. Corley, Z. Marka, S. Marka (Columbia) on behalf of the IceCube Collaboration The analysis FOUND A COINCIDENT ONLINE TRACK-LIKE NEUTRINO CANDIDATE detected by IceCube within the 500 second window surrounding LIGO/Virgo event candidate G299232 using the bayestar.fits.gz skymap. The coordinates of the reconstructed neutrino source are below: # dt[s] RA[deg] Dec[deg] E[TeV] Sigma[deg] ------------------------------------------------------------------ 1. -233.82 27.1 45.1 0.39 3.8 In an analysis completed at 2017-08-25 13:47:30 UTC, we searched IceCube online track-like neutrino candidates (GFU) detected in a [-500,500] second interval about the LIGO-Virgo trigger G299232. We compared the candidate source directions of 7 temporally-coincident neutrinos to the BAYESTAR skymap, with the following parameters: # dt[s] RA[deg] Dec[deg] E[TeV] Sigma[deg] ------------------------------------------------------------------ 1. -233.82 28.2 44.8 0.39 3.8 2. -230.58 286.6 4.9 1.08 0.7 3. -213.50 104.1 -0.8 1.46 0.3 4. 131.55 285.1 48.7 0.76 0.7 5. 227.96 113.9 -56.6 160.86 0.5 6. 367.52 64.8 -10.6 2.39 0.3 7. 485.21 9.1 -21.5 7.75 0.3 (dt--time from GW in [seconds]; RA/Dec--sky location in [degrees]; E--reconstructed secondary muon energy in [TeV]; Sigma--uncertainty of direction reconstruction in [degrees]) A coincident neutrino-GW skymap has been posted to GraceDB (). A JSON-formatted list of the above neutrinos can be downloaded from GraceDB at: In addition, we are performing coincident searches with other IceCube data streams, including the high-energy starting events (HESE) and Supernova triggers. HESE events have typical energies > 60 TeV and start inside the detector volume, leading to a relatively pure event sample with a high fraction of astrophysical neutrinos. The SN trigger system is sensitive to sudden increases in photomultiplier counts across the detector, which could indicate a burst of MeV neutrinos. We will submit separate GCN circulars if coincident HESE or SN triggers are found. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. For a description of the IceCube realtime alert system, please refer to ; for more information on joint neutrino and gravitational wave searches, please refer to . //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21696 SUBJECT: LIGO/Virgo G299232 ANTARES search DATE: 17/08/25 15:20:04 GMT FROM: Damien Dornic at CPPM/CNRS M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (IFIC & APC), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite Paris Diderot), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration: Using on-line data from the ANTARES detector, we have performed a follow-up analysis of the recently reported LIGO/Virgo G299232 event using the Bayestar-HLV probability map at event time. The ANTARES visibility at the time of the alert together with the 50% and 90% contours of the probability map are shown in: https://www.cppm.in2p3.fr/~dornic/events/G299232/250817_visibility2.png (gwantares/GW@ANT51). Considering the location probability provided by the LIGO collaboration, there is a 42% chance that the GW emitter was in the ANTARES field of view. No up-going muon neutrino candidate events were recorded in the ANTARES sky during a +/- 500s time-window centered on the G299232 event time. The expected number of atmospheric background events in the region visible by ANTARES is ~1.1e-2 in the +/- 500s time window. An extended search during +/- 1 hour gives no up-going neutrino coincidence. The results of the second analysis covering the full sky as well as an estimate of the upper limit on the associated neutrino fluence will be sent in a subsequent circular. ANTARES, being installed in the Mediterranean Deep Sea, is the largest neutrino detector in the Northern Hemisphere. It is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is below 0.5 degrees. In the range 1-100 TeV, ANTARES has the best sensitivity to a large fraction of the Southern sky. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21698 SUBJECT: LIGO/Virgo G299232: COINCIDENT IceCube neutrino observation UPDATE DATE: 17/08/25 15:52:28 GMT FROM: Stefan Countryman at LIGO Scientific Collaboration I. Bartos, S. Countryman (Columbia), C. Finley (U Stockholm), E. Blaufuss (U Maryland), R. Corley, Z. Marka, S. Marka (Columbia) on behalf of the IceCube Collaboration In GCN 21694 we reported the identification of an IceCube neutrino candidate that is temporally (within [-500s,500s]) and directionally (within 90% CL) coincident with LIGO/Virgo G298048. We reran our analysis using the updated three-detector skymap, bayestar-HLV.fits.gz. The same neutrino candidate is still COINCIDENT with the updated map. The properties of the neutrino candidate are below: # dt[s] RA[deg] Dec[deg] E[TeV] Sigma[deg] ------------------------------------------------------------------ 1. -233.82 28.2 44.8 0.39 3.8 (dt--time from GW in [seconds]; RA/Dec--sky location in [degrees]; E--reconstructed secondary muon energy in [TeV]; Sigma--uncertainty of direction reconstruction in [degrees]) A coincident neutrino-GW skymap has been posted to GraceDB (). A JSON-formatted list of the neutrinos used can be downloaded from GraceDB at: //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21699 SUBJECT: LIGO/Virgo G299232: INTEGRAL search for a prompt gamma-ray counterpart DATE: 17/08/25 17:06:50 GMT FROM: Volodymyr Savchenko at APC,Paris V. Savchenko (ISDC, University of Geneva, CH) on behalf of the INTEGRAL group: S. Mereghetti (IASF-Milano, Italy), C. Ferrigno ((ISDC, University of Geneva, CH), E. Kuulkers (ESTEC/ESA, The Netherlands), A. Bazzano (IAPS-Roma, Italy), E. Bozzo, T. J.-L. Courvoisier (ISDC, University of Geneva, CH) S. Brandt (DTU - Denmark) R. Diehl (MPE-Garching, Germany) L. Hanlon (UCD, Ireland) P. Laurent (APC, Saclay/CEA, France) A. Lutovinov (IKI, Russia) J.P. Roques (IRAP, France) R. Sunyaev (IKI, Russia) P. Ubertini (IAPS-Roma, Italy) We investigated serendipitous INTEGRAL observations carried out at the time of the LIGO/Virgo GW event candidate G299232. The satellite was pointing at RA=262.993 Dec=-27.052, near the lower-probability arc of LIGO/Virgo localization. About 10% of LIGO localization probability was in IBIS and SPI FoV. Depending on the location within LIGO 90% confidence region the best upper limit is set by the anti-coincidence shield of the spectrometer on board of INTEGRAL (SPI/ACS), IBIS/ISGRI, or IBIS/PICsIT. A fraction of the localization of G299232 is not optimal for SPI-ACS observation. The INTEGRAL IBAS automatically inspects both ISGRI Field of View and all-sky SPI-ACS light curve. It did not reveal any significant excess above the background. We investigated the SPI-ACS, IBIS/PICsIT, and IBIS/ISGRI light curves between -500 and +500 s from the trigger time (2017-08-25 13:13:37 UTC) on temporal scales from 0.1 to 100 s, and found no evidence for any significant deviation from the background. We estimate a median 3-sigma upper limits in 90% LIGO localization region of 1.0e-6 erg/cm2 (75-2000 keV) assuming a duration of 8s and Band model parameters alpha=-1, beta=-2.5, and E_ peak = 300 keV. To derive a limit for a typical short burst with 1 s duration, we use a harder cutoff power law spectrum with a photon index of -0.5 and an Epeak = 500 keV. We find a median limiting fluence of 3.6e-7 erg/cm2 (75-2000 keV) at 3 sigma c.l. For the fraction of LIGO/Virgo localization probability within the Field of View of INTEGRAL pointing instruments (IBIS, JEM-X, and SPI), the combination of these instruments allows to set stringent upper limit in a broad energy range from 3 keV to 8 MeV (Savchenko et al 2017 A&A...603A..46S). Further analysis of these data is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21700 SUBJECT: LIGO/Virgo G299232: AGILE MCAL detection of a short gamma-ray candidate DATE: 17/08/25 17:42:16 GMT FROM: Francesco Verrecchia at ASDC, INAF-OAR M. Cardillo (INAF/IAPS), F. Verrecchia (SSDC and INAF/OAR), M. Pilia (INAF/OA-Cagliari), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), G. Piano (INAF/IAPS),A. Bulgarelli (INAF/IASF-Bo), C. Pittori (SSDC and INAF/OAR), A.Ursi (INAF/IAPS),I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste),G. Minervini, A. Argan, Y. Evangelista (INAF/IAPS), F. Lucarelli (SSDC and INAF/OAR), N. Parmiggiani, A. Zoli, V. Fioretti, F. Fuschino (INAF/IASF-Bo), A. Trois (INAF/OA-Cagliari) M. Marisaldi (INAF/IASF-Bo and Bergen University), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: In response to the LIGO/Virgo GW event G299232 (T0=2017-08-25 13:13:37.983 UT; GCN #21693), we performed a preliminary AGILE Mini-CALorimeter (MCAL) data analysis on the time interval T0 -/+100s. In the nearest data acquisition starting at T1=T0+45s we detected a short burst occurring about at T0+47s which triggered both the on-board 16 ms and 64 ms timescale hardware logics. The MCAL light curve shows a sharp single peak that lasted about 1 sec and has a total number of ~1333 counts above 400 keV in the detector, above an average background rate of 614 counts/s. Additional analysis of AGILE MCAL data is in progress, to further verify possible spurious contaminations of this detection. The AGILE-MCAL detector has a full solid angle acceptance, and is operational in the range 0.4 - 100 MeV. The MCAL current trigger rate is on average ~ 0.15 every 20 sec. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21701 SUBJECT: LIGO/Virgo G299232: AGILE GRID observations DATE: 17/08/25 17:58:16 GMT FROM: Francesco Verrecchia at ASDC, INAF-OAR G. Piano, M. Cardillo (INAF/IAPS), F. Verrecchia (SSDC and INAF/OAR), M. Pilia (INAF/OA-Cagliari), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Bulgarelli (INAF/IASF-Bo), C. Pittori (SSDC and INAF/OAR), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste), A. Ursi, G. Minervini, A. Argan, Y. Evangelista (INAF/IAPS), F. Lucarelli (ASDC and INAF/OAR), N. Parmiggiani, A. Zoli, V. Fioretti, F. Fuschino (INAF/IASF-Bo), A. Trois (INAF/OA-Cagliari) M. Marisaldi (INAF/IASF-Bo and Bergen University), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: In response to the LIGO/Virgo GW trigger event G299232 at T0 = 2017-08-25 13:13:37.983 UTC (GCN #21693), we performed an analysis of the AGILE Gamma-Ray Imaging Detector (GRID) data on different timescales. On LIGO/Virgo trigger time (T0) the GRID exposure covered nearly 42% of the LIGO/Virgo localization region (at 90% confidence level; LR), observed at off-axis angles between 20 and 55 deg. An analysis of the data in the energy range 50 MeV - 10 GeV was performed on timescales from 2 to 100 sec centered at T0. Preliminary values of 3-sigma upper limits (ULs) obtained within the accessible LIGO/Virgo 3-sigma LR are reported below: from 1.5e-06 to 7.8e-06 erg cm^-2 s^-1 for integration time of 2s from 1.5e-07 to 7.8e-07 erg cm^-2 s^-1 for integration time of 20s from 3.9e-08 to 2.2e-07 erg cm^-2 s^-1 for integration time of 100s These measurements were obtained with AGILE observing a large portion of the sky in spinning mode. Additional analysis of AGILE data is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21704 SUBJECT: LIGO/Virgo G299232: Swift/BAT data search DATE: 17/08/25 22:47:30 GMT FROM: Amy Lien at GSFC/Swift T. Sakamoto (AGU), S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), A. A. Breeveld (MSSL-UCL), A. P. Beardmore (U. Leicester), D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V. D'Elia(ASDC), S. Emery (UCL-MSSL), P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), B. Mingo (U. Leicester), J. A. Nousek (PSU), S. R. Oates (Uni. of Warwick), P. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), K. L. Page (U.Leicester), M. Perri (ASDC), J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU), E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team: We report the search results in the BAT data within T0 +/- 100 s of the LVC event G299232 (LIGO/VIRGO Collaboration GCN Circ. 21693), where T0 is the LVC trigger time (2017-08-25T13:13:31 UTC). The center of the BAT FOV at T0 is RA = 253.402 deg, DEC = 39.751 deg, ROLL = 288.107 deg. The BAT Field of View (>10% partial coding) covers 11.56% of the integrated LVC localization probability. Within T0 +/- 100 s, no significant detections (signal-to-noise ratio >~ 5 sigma) are found in the BAT raw light curves with time bins of 64 ms, 1 s, and 1.6 s, respectively. The short spike appears at ~T-93 s in the 64-ms and 1-s light curve is consistent with a glitch caused by detector noise, because it is only seen in one single time bin and in the 15-25 keV band, and no significant detection in the image domain. Assuming an on-axis (100% coded) short GRB with a typical spectrum in the BAT energy range (i.e., a simple power-law model with a power-law index of -1.32, Lien & Sakamoto et al. 2016), the 5-sigma upper limit in the 1-s binned light curve corresponds to a flux upper limit (15-350 keV) of ~ 1.22 x 10^-7 erg/s/cm^2. BAT retains decreased, but significant, sensitivity to rate increases for gamma-ray events outside of its FOV. About 27.56% of the integrated LVC localization probability was outside of the BAT FOV but above the Earth's limb from Swift's location, and the corresponding flux upper limits for this region are within roughly an order of magnitude of those within the FOV. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21707 SUBJECT: LIGO/Virgo G299232: Nearby Galaxies in the Localization Volume DATE: 17/08/26 01:19:16 GMT FROM: Mansi M. Kasliwal at Caltech David O. Cook (Caltech), Angela Van Sistine (UW Milwaukee), Leo Singer (NASA/GSFC), M. M. Kasliwal (Caltech), and David Kaplan (UW Milwaukee) report on behalf of the iPTF and GROWTH collaborations We spatially cross-matched the LIGO/Virgo G299232 trigger (90% containment volume using bayestar-HLV.fits; LVC GCN 21693) with our Census of the Local Universe (CLU; Cook et al. in prep) galaxy catalog and found 17,593 galaxies. This catalog is a compilation of galaxies with existing redshifts from many sources (e.g., NED, SDSS, etc) and new galaxies from a 3PI four-filter narrow-band survey to look for redshifted Halpha emission out to 200 Mpc with the Palomar Oschin 48-inch telescope. Currently, the narrow-band survey is only calibrated inside the footprint of SDSS. Of the 17,593 galaxies in the error volume, 17,120 come from a compilation of known galaxies and 473 are new, emission-line CLU galaxy candidates derived from our Halpha survey. We list here the top 20 galaxies sorted by stellar mass (Mstar) for galaxies whose location on the sky and distance falls in the 90% volume reported by the BAYESTAR probability sky map (Singer et al. 2016). We also list the dust-corrected star formation rates (SFRs) for galaxies with GALEX FUV detections and a 'nan' for those with no detection. name_NED ra dec distmpc logsfr_fuv logmstar P ----------------------------------------- -------- -------- ------- ---------- -------- --------------- [HB89] 0241+622 41.2405 62.4685 191.43 nan 12.05 0.140963304855 LDCE 1285 271.5879 -25.4311 103.44 nan 11.91 0.800186835374 ESO 344- G 016 333.6750 -38.8064 170.09 1.540 11.72 0.886386086915 UGC 00774 18.4626 13.2719 209.58 1.593 11.69 0.528731713093 IC 0260 42.7537 46.9548 123.80 nan 11.54 0.882625900958 6dF J1741553-121157 265.4803 -12.1990 152.05 nan 11.44 0.753441530388 NGC 0326 NED01 14.5943 26.8662 208.72 -0.405 11.33 0.7901652699 NGC 6958 312.1785 -37.9975 99.86 nan 11.31 0.789778583289 2MASX J01571097+4715588 29.2956 47.2666 207.11 nan 11.30 0.281525733779 IC 1695 21.2818 8.6995 210.38 nan 11.30 0.431687269372 UGC 01400 29.0184 36.1313 77.62 nan 11.29 0.335875843118 NGC 6099 243.8982 19.4534 207.50 nan 11.28 0.714631039094 MRK 0567 19.8255 4.5781 141.83 1.304 11.26 0.572392023225 NGC 6240 NED01 253.2453 2.4010 100.61 nan 11.26 0.752082522541 SDSS J005601.73-010352.2 14.0072 -1.0645 189.66 nan 11.26 0.737619298894 2MASX J01543532+6437570 28.6470 64.6326 149.45 nan 11.26 0.593543567206 2MASX J20145535-3240004 303.7306 -32.6668 409.11 nan 11.24 0.892450247448 UGC 00959 21.1875 32.1657 173.33 0.907 11.24 0.422381064489 SDSS J162220.44+115214.9 245.5852 11.8708 215.90 nan 11.21 0.636472864491 GALEXASC J015114.07+223457.6 27.8086 22.5827 133.44 nan 11.20 0.34030312252 The SFRs are derived from GALEX all sky kron FUV magnitudes via the prescription of Murphy et al. (2011) and have been corrected for internal dust extinction using a combination of GALEX FUV and 22um ALLWISE fluxes (Hao et al. 2011). The quoted stellar masses are derived from 3.4um ALLWISE fluxes and a mass-to-light ratio of 0.5 (McGaugh & Schombert et al. 2015). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21710 SUBJECT: LIGO/Virgo G299232 : Fermi-LAT search for high-energy gamma-ray counterpart DATE: 17/08/26 02:53:20 GMT FROM: Daniel Kocevski at NASA/MSFC D. Kocevski (NASA/Marshal), G. Vianello (Stanford), N. Omodei (Stanford), S. Buson (NASA/GSFC), N. Di Lalla (Univ. Pisa & INFN Pisa), and M. Razzano (Univ. Pisa & INFN Pisa) report on behalf of the Fermi-LAT team: We searched data collected by the Fermi Large Area Telescope (LAT) for a possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger G299232 (GCN 21693). At the time of the trigger (T0 = 2017-08-25 13:13:37.977 UTC, 525359622.977 MET), 40% of the LIGO/Virgo Bayestar probability map based on L1, H1, and V1 observations was in the LAT field of view, and we reached 100% cumulative coverage within ~5400 s after the trigger. We define "instantaneous coverage" as the integral over the region of the probability map that is within the LAT field of view at a given time, and "cumulative coverage" as the integral of the instantaneous coverage over time. We performed a search for a transient counterpart within the 90% contour of the probability map in the time window from T0 to T0 + 10 ks, and no significant new sources are found. We also performed a search which adapted the time interval of the analysis to the exposure of each region of the sky. No significant candidate counterpart was found. The Fermi-LAT point of contact for this event is Daniel Kocevski (daniel.kocevski@nasa.gov) The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21711 SUBJECT: LIGO/VIRGO G299232: Fermi GBM Observations DATE: 17/08/26 03:11:21 GMT FROM: Rachel Hamburg at UAH LIGO/VIRGO G299232: Fermi GBM Observations R. Hamburg (UAH) reports on behalf of the GBM-LIGO Group: L. Blackburn (CfA), M. S. Briggs (UAH), J. Broida (Carleton College), E. Burns (NASA/GSFC), J. Camp (NASA/GSFC), T. Dal Canton (NASA/GSFC), N. Christensen (Carleton College), V. Connaughton (USRA), A. Goldstein (USRA), C.M. Hui (NASA/MSFC), P. Jenke (UAH), D. Kocevski (NASA/MSFC), N. Leroy (LAL), T. Littenberg (NASA/MSFC), J. McEnery (NASA/GSFC), R. Preece (UAH), J. Racusin (NASA/GSFC), P. Shawhan (UMD), K. Siellez (GATech), L. Singer (NASA/GSFC), J. Veitch (Birmingham), P. Veres (UAH), C. Wilson-Hodge (NASA/MSFC) At the G299232 event time (2017-08-25 13:13:37 UTC), Fermi GBM was taking data and viewing the entire un-occulted sky approximately 67 degrees from Earth center (RA = 54.6,Dec = 7.8), which includes 36% of the LIGO BAYESTAR HLV map. No on-board triggers occurred within an hour of the GW trigger time. The untargeted ground-based search of GBM data for short-duration GRBs (Briggs et al., in prep) also did not find any significant candidate within one hour of the GW trigger. The targeted search of the GBM data ([1],[2]) searched +/- 30 s around the GW event time, processing time scales of 0.256 to 8.192 s. One event with a soft spectrum was found on a 4 s timescale approximately 27 s after the GW time. The initial estimated False Alarm Rate (FAR) is 4.6e-4 Hz (90% confidence). The localization returned by the search does not overlap with the LHV Bayestar localization region. We conclude that this signal is unassociated with the GW event. The targeted search was also run +/- 30 s around the gamma-ray candidate reported by AGILE MCAL (Carrillo et al., 2017, GCN 21700). No significant candidates were found. [1] L. Blackburn et al. 2015, ApJS 217, 8 [2] A. Goldstein et al. arXiv:1612.02395 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21712 SUBJECT: LIGO/Virgo G299232: Astrosat CZTI upper limits DATE: 17/08/26 09:36:29 GMT FROM: Varun Bhalerao at Indian Inst of Tech Arvind Balasubramanian (IISER Pune), Varun Bhalerao (IUCAA), Dipankar Bhattacharya (IUCAA), Sukanta Bose (IUCAA), Gulab Chand Dewangan (IUCAA), Ranjeev Misra (IUCAA), Sanjit Mitra (IUCAA), A R Rao (TIFR), Tarun Souradeep (IUCAA), Santosh Vadawale (PRL), on behalf of the Astrosat CZTI team report: We carried out offline analysis of data from Astrosat CZTI in a 100 second window centred on the G298048 trigger time, 2017-08-25 13:13:31 UTC, to look for any coincident hard X-ray flash. CZTI is a coded aperture mask instrument that has considerable effective area for about 29% of the entire sky. Based on the pointing direction of Astrosat at the time of the GW event and the Bayestar skymap provided by LVC (bayestar-HLV.fits.gz), the sky visible to CZTI has 58.3% probability of containing the EM counterpart. CZTI data were de-trended to remove orbit-wise background variation. We then searched data from the four independent, identical quadrants to look for coincident spikes in the count rates. Searches were undertaken by binning the data in 0.1s, 1s and 10s respectively. Statistical fluctuations in count rates were estimated by using data from 5 previous orbits. We selected confidence levels such that the probability of a false trigger in this 100s window is 10^-4. We do not find any evidence for any hard X-ray transient in this window. In particular, we do not detect the AGILE MCAL candidate reported by Cardillo et al (GCN 21700). We convert our count rates into fluence and flux limits by assuming that the source spectrum has band parameters alpha = -1.0, beta = -2.5, Epeak = 300. The upper limits for source fluence and flux in a 30-200 keV band at different timescales are: Calculating fluxes assuming band parameters alpha = -1.0, beta = -2.5, Epeak = 300 0.1 s: Effective fluence limit= 3.52e-7 ergs/cm^2; flux= 3.52e-6 ergs/cm^2/s 1.0 s: Effective fluence limit= 7.89e-7 ergs/cm^2; flux= 7.89e-7 ergs/cm^2/s 10.0s: Effective fluence limit= 1.06e-6 ergs/cm^2; flux= 1.06e-7 ergs/cm^2/s The corresponding all-sky maps are uploaded at https://gracedb.ligo.org/apiweb/events/G299232/files/G299232_CZTI_limits.pdf,0 CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21713 SUBJECT: LIGO/Virgo G299232: XRT Rank 2 source is not real DATE: 17/08/26 11:49:24 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Our automated analysis of the XRT follow up of G299232 recently reported an apparent Rank 2 source as a GCN Counterpart Notice. Manual inspection of the images shows that the “source" lies in a region of extended diffuse emission, likely caused by partial illumatination of the CCD by scattered light from the bright Earth limb. We do not consider this source to be astrophysical in origin. The counterpart notices are preliminary, as they are generated entirely automatically. This circular is an official product of the Swift team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21716 SUBJECT: LIGO/Virgo G299232: CALET Observations DATE: 17/08/27 01:29:15 GMT FROM: Takanori Sakamoto at Aoyama Gakuin U S. Ozawa (Waseda U), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena) and the CALET collaboration: The CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger time of G299232 (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 21693). No CGBM on-board trigger occurred at the time of the event. Based on the LIGO-Virgo localization sky map (bayestar-HLV.fits.gz), the part of the northern arc of the high probability area was in the field-of-view of CGBM. The summed LIGO probabilities inside the HXM and the SGM field of view are 70% and 72%. Based on the analysis of the light curve data with 0.125 sec time resolution from -60 sec to 60 sec from the trigger time, we found no significant excess around the trigger time in either the HXM (7-3000 keV) or the SGM (40 keV -28 MeV) data. The CALET Calorimeter (CAL) was operating in high energy trigger mode at the trigger time of G299232. Similar to CGBM, the northern arc of the high probability area of the LIGO-Virgo localization map was in the field of view of CAL. Using CAL data, we have searched for gamma-ray events in the 10-100 GeV band from -60 sec to +60 sec from the GW trigger time and found no candidates. The 90% upper limit of CAL is 2e-4 erg/cm2/s (10-100 GeV) when the summed LIGO-Virgo probabilities reaches at 20%. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21719 SUBJECT: LIGO/Virgo G299232/PGWB170825.55: MASTER Global-Net OT inside NGC1343 discovery DATE: 17/08/27 08:01:19 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.M.Lipunov, E. Gorbovskoy, V.G.Kornilov, N.Tyurina, V.Shumkov, D.Kuvshinov, P.Balanutsa, O.Gress, A.Kuznetsov, M.I.Panchenko, A.V.Krylov, I.Gorbunov Lomonosov Moscow State University, Sternberg Astronomical Institute V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk N.M. Budnev, O. Gress, K. Ivanov, S.Yazev Irkutsk State University A. Tlatov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory R.Podesta, C.Lopez, F.Podesta Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina H.Levato, C.Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina D.Buckley, S.Potter, M.Kotze, South African Astronomical Observatory R. Rebolo, M. Serra-Ricart, G. Israelian, N.Lodiu The Instituto de Astrofisica de Canarias Global MASTER robotic net automatically starting folow-up inspection of the bayestar-HLV map of the G299232/PGWB170825.55* event time (2017-08-25 13:13:37 UTC, LVC GCM 21693) by 7 robots MASTER telescopes. Table I. Time starting MASTER-Net follow-up observations. Site | UT start | T-Ttrig, Ks ------------------|-------------------------|-------- MASTER-SAAO | 2017-08-25 20:06:39.328 | 24.782 MASTER-Kislovodsk | 2017-08-25 20:09:22.169 | 24.945 MASTER-IAC | 2017-08-25 20:28:20.207 | 26.083 MASTER-OAFA | 2017-08-25 23:08:25.365 | 35.688 MASTER-Amur | 2017-08-26 11:37:19.06 | 80.622 MASTER-Tunka | 2017-08-26 13:28:02.508 | 87.265 MASTER OTJ033744.97+723159.0 discovery near NGC1343. MASTER-Kislovodsk auto-detection system discovered OT source at (RA, Dec) = 03h 37m 44.97s +72d 31m 59.0s on 2017-08-27.01649 UT. The OT unfiltered magnitude is 17.0m (limit 18.2m). The OT is seen in 4 images. There is no minor planet at this place. We have reference image without OT on 2012-12-17.70730 UT with unfiltered magnitude limit 19.4m. The discovery and reference images are available at http://master.sai.msu.ru/static/OT/033744.97723159.0.png The MASTER covering map is available at http://master.sai.msu.ru/static//ligo/db/G299232/151//img/MASTER.G299232.000.12.gif *PGWB170825.55 - Possible Gravitational Wave Burst 2017 Aug 25.55 UT - internal disignation for electromagnetic people. This message can be citted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21720 SUBJECT: LIGO/Virgo G299232/PGWB170825.55: MASTER OTJ033744.97+723159.0 off set from NGC1343 galaxy DATE: 17/08/27 08:12:12 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.M.Lipunov, E. Gorbovskoy, V.G.Kornilov, N.Tyurina, V.Shumkov, D.Kuvshinov, P.Balanutsa, O.Gress, A.Kuznetsov, M.I.Panchenko, A.V.Krylov, I.Gorbunov Lomonosov Moscow State University, Sternberg Astronomical Institute V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk N.M. Budnev, O. Gress, K. Ivanov, S.Yazev Irkutsk State University A. Tlatov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory R.Podesta, C.Lopez, F.Podesta Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina H.Levato, C.Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina D.Buckley, S.Potter, M.Kotze, South African Astronomical Observatory R. Rebolo, M. Serra-Ricart, G. Israelian, N.Lodiu The Instituto de Astrofisica de Canarias Smal edition to GCN LVC GCN 21719 . MASTER OTJ033744.97+723159.0 off set from the center of the NGC1343 are: 21W 137.9S. The spectroscopic observations are requared. This message can be citted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21723 SUBJECT: LIGO/Virgo G299232: Transient near NGC 1343 has a somewhat blue r-i color DATE: 17/08/27 16:45:39 GMT FROM: Myungshin Im at Seoul National U M. Im, C. Choi, G. Lim, J. Kim, H. M. Lee (SNU), M. J. Kim, H. J. Lee (KASI) on behalf of the KU collaboration We obtained r, i, and z-band images of MASTER OTJ033744.97+723159.0 near NGC 1343 (Lipunov et al. GCN 21719, 21720), a candidate counterpart of G299232/PGW170826 (Siellez et al. GCN 21693). The data were taken with SQUEAN instrument on the McDonald Observatory’s 2.1m telescope at 2017-08-27, 10:57 (UT). Before Galactic extinction correction, it has r = 16.67 +- 0.03 and i = 16.71 +- 0.03 (AB mag), with r-i color of r –i ~ -0.04 mag. However, after Galactic extinction correction, we get r= 15.89 and i = 16.13 and r-i = -0.24 mag, a rather blue color in comparison to G298048 shortly after its discovery (Nicholl et al. GCN 21541). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21725 SUBJECT: LIGO/Virgo G299232: LOFAR follow-up DATE: 17/08/27 19:08:16 GMT FROM: Antonia Rowlinson at U van Amsterdam A. Rowlinson (UvA, ASTRON), J.W. Broderick (ASTRON), P.G. Jonker (SRON, RU), R.P. Fender (Oxford), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester), S. ter Veen (ASTRON), S. Nissanke (RU) and A. Shulevski (ASTRON) report on behalf of the LOFAR Transients Key Science Project On 2017 August 25, we conducted a LOFAR follow-up observation of the Advanced LIGO/Virgo trigger G299232 with the ILT (International Low-Frequency Array [LOFAR] Telescope). The observation began at 14:47:31 UTC. The observations were obtained with the high-band antennas (HBA) at a centre frequency of 145 MHz (bandwidth 11.9 MHz). We used 8 simultaneous beams on the sky, where each beam has a field of view of approximately 12 deg^2 (beam FWHM 3.9 deg at 150 MHz). The observations cover roughly 50 deg^2 in total at optimum sensitivity. Each field was observed in both imaging and beamformed modes for a total of 120 min. The beam centres (RA/Dec), in degrees, are as follows: 1) 27.8625 50.4931 2) 30.6384 50.4931 3) 25.0866 50.4931 4) 29.2505 52.8971 5) 26.4745 52.8971 6) 29.2505 48.0890 7) 26.4745 48.0890 8) 28.6250 57.4389 Analysis is ongoing. We thank the ASTRON Radio Observatory for rapidly scheduling the observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21726 SUBJECT: LIGO/Virgo G299232: OVRO-LWA simultaneous low frequency radio observations of localization region DATE: 17/08/27 19:44:56 GMT FROM: Marin M Anderson at Caltech M. M. Anderson (Caltech) and G. Hallinan (Caltech) on behalf of the OVRO-LWA collaboration. The OVRO-LWA was observing prior, during and after the detection of LIGO/Virgo G299232, with continuous frequency coverage from 30 MHz to 85 MHz and a field-of-view covering the entire northern hemisphere arc of the 90% localization region (bayestar-HLV.fits.gz, LVC GCN #21693). Data reduction and analysis have commenced investigating the possible presence of a low frequency prompt counterpart to the event, focusing on observations spanning 1 hour prior to and 3 hours following the detection of LIGO/Virgo G299232, from 2017-08-25 12:13 UTC to 16:13 UTC. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21731 SUBJECT: LIGO/Virgo G299232 TZAC/TAROT observations DATE: 17/08/28 13:25:58 GMT FROM: Michel Boer at CESR-CNRS M. Boer, R. Laugier (CNRS/ARTEMIS/UCA/OCA), A. Klotz (CNRS/IRAP/UPS), K. Noysena (ARTEMIS/IRAP/CNRS/UPS), report on behalf the TZAC collaboration: We have observed part of the localization of the LIGO/Virgo candidate G299232 during the nights 2017-08-25 from 19h12 UT with TRE (5 fields, total 80sq. deg.) and TCA (5 fields, total 18sq.deg.). The position of the center of the fields are reported below. Analysis is ongoing. Site RA DEC Start of the observations (UT) TCA 02:06:31 40:39:53 2017-08-25T19:43:50.376 TCA 02:03:52 38:48:17 2017-08-25T19:48:10.376 TCA 02:09:21 42:31:29 2017-08-25T19:28:20.376 TCA 02:01:22 36:56:41 2017-08-25T19:56:50.376 TCA 02:12:23 44:23:05 2017-08-25T19:12:50.376 TRE 02:04:08 40:12:00 2017-08-25T21:04:09.792 TRE 02:00:24 36:00:00 2017-08-25T20:28:39.792 TRE 01:53:50 40:12:00 2017-08-25T20:35:09.792 TRE 01:53:14 36:00:00 2017-08-25T19:59:39.792 TRE 01:56:40 31:48:00 2017-08-25T20:06:09.792 TRE 02:26:07 40:12:00 2017-08-25T20:54:39.792 Note: TRE TAROT-La Réunion; TCA TAROT-Calern //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21733 SUBJECT: LIGO/Virgo G299232: Optical Transient Discovery by Swift/UVOT DATE: 17/08/28 18:13:59 GMT FROM: Samuel Emery at UCL-MSSL/Swift S.W.K. Emery (UCL-MSSL), A.A. Breeveld (UCL-MSSL), F.E. Marshall (NASA/GSFC), S.R. Oates (Uni. of Warwick), N.P.M. Kuin (UCL-MSSL), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester), D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G. Cusumano(INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V.D'Elia(ASDC), P.A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU), J.A. Kennea (PSU), H.A. Krimm (CRESST/GSFC/USRA), A.Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), P.T. O'Brien (U. Leicester), J.P. Osborne (U. Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU), E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team: Swift has performed a series of 525 observations, covering 497 separate locations within the LVC error region for the GW trigger G299232 convolved with the 2MPZ catalogue (Bilicki et al. 2014, ApJS, 210, 9), using the 'bayestar-HLV' GW localisation map. The observations currently span from 11 ks to 256 ks after the LVC trigger. We have detected an uncatalogued source with the Swift/UVOT, at the position: RA(J2000) = 01h 40m 08.55s Dec(J2000)= +34d 34' 03.6" We obtain the following magnitude using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373): Filter Exp(s) Mag u 57 18.00 +/- 0.16 The 57-s exposure started at 2017-08-27 T12:02:34 (about 1.95 days after the LVC trigger). The magnitude is not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the source (Schlegel et al. 1998). No X-ray source was detected at this position, with a 0.3-10 keV upper limit of 0.13 ct/sec, which corresponds to 5.2e-12 erg/cm^2/s (assuming a typical AGN spectrum). There is no source in the DSS or SDSS at this position and there is no minor planet at this position. Further Swift observations are planned. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21736 SUBJECT: LIGO/Virgo G299232/PGWB170825.55: MASTER OT J033744.97+723159.0 inside 25m isophota of the NGC1343 galaxy is reddening DATE: 17/08/28 19:22:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.M.Lipunov, E. Gorbovskoy, V.G.Kornilov, N.Tyurina, V.Shumkov, D.Kuvshinov, P.Balanutsa, O.Gress, A.Kuznetsov, M.I.Panchenko, A.V.Krylov, I.Gorbunov Lomonosov Moscow State University, Sternberg Astronomical Institute R. Rebolo, M. Serra-Ricart, G. Israelian, N.Lodiu The Instituto de Astrofisica de Canarias V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk N.M. Budnev, O. Gress, K. Ivanov, S.Yazev Irkutsk State University A. Tlatov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory R.Podesta, C.Lopez, F.Podesta Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina H.Levato, C.Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina D.Buckley, S.Potter, M.Kotze, South African Astronomical Observatory MASTER OT J033744.97+723159.0 (lipunov, Gorbovskoy, Kornilov et al., GCN LVC GCN 21719, 21780) is cheked recently by MASTER-IAC (Tenerife, Spain). Our photometrical results are: Date Time JD Filter Mag A* Mag_cor 2017-08-27 22:46:16 2457993.4487963 B 18.12 1.41 16.71 2017-08-27 22:50:10 2457993.4515046 V 16.81 1.07 15.74 2017-08-27 22:50:10 2457993.4515046 R 16.04 0.80 15.24 2017-08-27 22:46:16 2457993.4487963 I 15.94 0.51 15.43 * for E(B-V) = 0.3436 and Av = 3.1 * E(B-V) = 1.065 =========================== Uncorrected magnitude: B = 18.1226 V = 16.8078 R = 16.0422 I = 15.9435 E(B-V) = 0.3436 (http://irsa.ipac.caltech.edu/applications/DUST/ ) Av = 3.1 * E(B-V) => Av = 1.06516 (http://www.astro.ncu.edu.tw/~wchen/Courses/ISM/11.Extinction.pdf page 17) => http://www.astro.ncu.edu.tw/~wchen/Courses/ISM/11.Extinction.pdf (page 22 ) So, MASTER OT J033744.97+723159.0 is reddening (cf, Im et al, LVC GCN 21723). The spectroscopic observations are requared. This message can be citted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21737 SUBJECT: LIGO/Virgo G299232: WHT spectrum of MASTER OT J033744.97+723159.0 DATE: 17/08/28 21:07:42 GMT FROM: Peter Jonker at SRON/RU P.G. Jonker (SRON/RU), M. Fraser (UCD), S. Nissanke (RU), R.P. Fender (Oxford), J. Broderick (ASTRON), A. Rowlinson (UvA, ASTRON), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester) report on behalf of the LOFAR Transients Key Science project: On Aug, 27, 2017, starting at 03.37 (UTC), we obtained three spectra with an exposure time of 900 sec each, with the ACAM instrument mounted on the William Herschel Telescope on La Palma (Spain) of the optical transient MASTER OTJ033744.97+723159.0 reported by Lipunov et al. (GCN 21720). Analysis using Gelato suggests that it is a supernova Type IIb before maximum taking the redshift of NGC1343 of 0.0073 as input. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21738 SUBJECT: LIGO/Virgo G299232: Continued observation of the transient near NGC 1343 DATE: 17/08/29 02:11:20 GMT FROM: Myungshin Im at Seoul National U M. Im, C. Choi, G. Lim, J. Kim, H. M. Lee (SNU), M. J. Kim, H. J. Lee (KASI) on behalf of the KU collaboration At 2017-08-28 11:00 (UT), we continued the observation of MASTER OTJ033744.97+723159.0 near NGC 1343 (Lipunov et al. GCN 21719, 21720) with the SQUEAN instrument on the McDonald Observatory’s 2.1m telescope. AB magnitudes before and after the Galactic extinction correction are given below. Before | Extinction | After g 16.97 1.125 15.85 r 16.49 0.778 15.71 i 16.56 0.578 15.98 The object has brightened by ~0.2 mag in one day and stayed blue in r-i but has a redder color in g-r (c.f. Lipunov et al. GCN 21736). The brightening is consistent with the report that this is a type IIb SN before maximum (Jonker et al. GCN 21737). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21741 SUBJECT: LIGO/Virgo G299232 : MAXI/GSC observations DATE: 17/08/29 05:46:53 GMT FROM: Satoshi Sugita at Tokyo Inst. of Tech. S. Sugita, N. Kawai (Tokyo Tech), M. Serino (RIKEN), H. Negoro (Nihon U.), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N.Isobe, R. Shimomukai (JAXA), T. Mihara, M. Sugizaki, S. Nakahira, W. Iwakiri, M. Shidatsu, M. Matsuoka (RIKEN), T. Yoshii, Y. Tachibana, S. Harita, Y. Muraki, K. Morita (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka, T. Hashimoto (AGU), H. Tsunemi, T. Yoneyama (Osaka U.), M. Nakajima, T. Kawase, A. Sakamaki (Nihon U.), Y. Ueda, T. Hori, A. Tanimoto, S. Oda (Kyoto U.), Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, C. Hanyu, K, Hidaka (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team: We examined the MAXI/GSC all-sky X-ray images (2-20 keV) obtained in the orbit and the day after the LVC trigger G299232 at 2017-08-25 13:13:31 UTC (GCN 21693). At the trigger time of G299232, the high-voltage of MAXI/GSC was off, and it was turned on at T0+1480 sec. GSC scanned more than 56% of the whole sky in the 92-min orbit, which includes 69.0% of the 90% region in the bayestar skymap. scanned from 13:13:31 UTC. One day image obtained between 08-25 13:13:31 and 08-26 12:03:01 UTC covers 99.0% of the 90% region in the bayestar skymap. No significant new source was found in these images and the 2-20 keV averaged photon counts in the skymap region is 0.41 counts/cm2/sec. The 3-sigma averaged upper limits obtained from the one-scan and one-day images in the bayestar skymap are 39 and 12 mCrab, respectively (see Serino et al., 2017 for the upper limit calculation). If you require information of X-ray flux by MAXI/GSC at specific coordinates, please contact the submitter of this circular by email. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21742 SUBJECT: LIGO/Virgo G299232: COATLI Observations of MASTER OT J033744.97+723159.0 DATE: 17/08/29 05:53:46 GMT FROM: Alan M Watson at UNAM Nat Butler (ASU), Alan M. Watson (UNAM), V. Zach Golkhou (University of Washington), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Eleonora Troja (GSFC), and Carlos Román-Zúñiga (UNAM) report: We observed the field of MASTER OT J033744.97+723159.0 (Lipunov et al., GCN Circ. 21719) with the COATLI 50-cm telescope and interim imager (Watson et al. 2016, Proc. SPIE, 9908, 50) at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir from 2017-08-28 03:13 to 12:05 obtaining a total of 2.21 hours of observation in the Bessell B and 1.79 hours in Bessell R. We detect the OT. Calibrating with respect to the USNO-B1 catalog, we estimate a preliminary magnitude of B = 17.21 +/- 0.01 R = 16.15 +/- 0.01 These magnitudes are in the USNO-B1 Vega system and are not corrected for Galactic extinction in the direction of the OT. Using the Lupton (2005) conversion from B-R to g-r, we find good agreement between our B-R = 1.06 color and the g-r color reported by Im et al. (GCN 21738). However, our color is much bluer than the B-R = 2.06 color of Lipunov et al. (GCN 21736). We thank the COATLI technical team (Fernando Ángeles, Rosa Becerra, Oscar Chapa, Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosalía Langarica, Fernando Quirós, and Carlos Tejada) and the staff of the Observatorio Astronómico Nacional. -- Dr. Alan M. Watson Instituto de Astronomía Universidad Nacional Autónoma de México //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21745 SUBJECT: LIGO/Virgo G299232: GRAWITA Asiago/Copernico Telescope observations DATE: 17/08/29 10:29:47 GMT FROM: Stefano Benetti at INAF-OAPd L. Tomasella, S. Benetti, E. Cappellaro (INAF-OAPD), L. Amati (INAF-IASF Bo), L. A. Antonelli, S. Ascenzi (INAF-OAR), M.T. Botticella (INAF-OAC), M. Branchesi (GSSI), S. Campana, S. Covino, P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-ASDC), D. Fugazza, F. Getman, A. Grado (INAF-OAC), G. Greco (Urbino University/INFN Firenze), L. Limatola (INAF-OAC), M. Lisi (INAF-OAR), A. Melandri (INAF-OAB), L. Nicastro, E. Palazzi, E. Pian (INAF-IASF Bo), S. Piranomonte, L. Pulone (INAF-OAR), A. Rossi (INAF-IASF Bo), P. Schipani (INAF-OAC), G. Stratta (Urbino University/INFN Firenze), G. Tagliaferri (INAF-OAB), V. Testa (INAF-OAR), S. Yang (INAF-OAPD), E. Brocato (INAF-OAR) on behalf of GRavitational Wave Inaf TeAm report: We observed the field of the Optical Transient Discovery by Swift/UVOT (LVG GCN 21733) with the Asiago 1.82 m Copernico Telescope equipped with AFOSC under poor sky conditions. We do not detected the Swift OT down to the following limits: Filter (SDSS) average UT total Exp (s) limit (ABmag) u 20170828.90 1800 22.5 g 20170828.89 270 21.6 r 20170828.88 270 20.8 i 20170828.93 270 21.9 z 20170828.92 900 21.4 We note the presence of the galaxy UGC 1178 at about 5 arcmin from the position of the OT. This galaxy has a redshift z=0.018399, and the projected distance of the OT seen by UVOT would then correspond to about 120 Kpc from the galaxy center. [GCN OPS NOTE(29aug17): Per author's request, The Subject-line was changed from "...INAF Asiago/Copernico..." to "...GRAWITA Asiago/Copernico...". And the the last paragraph "UGC 1178a" was changed to "UGC 1178". //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21749 SUBJECT: LIGO/Virgo G299232/PGWB170825.55: early MASTER observations of the Swift UVOT source position DATE: 17/08/29 13:17:59 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.M.Lipunov, E. Gorbovskoy, V.G.Kornilov, N.Tyurina, V.Shumkov, D.Kuvshinov, P.Balanutsa, O.Gress, A.Kuznetsov, M.I.Panchenko, A.V.Krylov, I.Gorbunov Lomonosov Moscow State University, Sternberg Astronomical Institute R. Rebolo, M. Serra-Ricart, G. Israelian, N.Lodiu The Instituto de Astrofisica de Canarias V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk N.M. Budnev, O. Gress, K. Ivanov, S.Yazev Irkutsk State University A. Tlatov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory R.Podesta, C.Lopez, F.Podesta Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina H.Levato, C.Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina D.Buckley, S.Potter, M.Kotze, South African Astronomical Observatory We observed field with Swift/UVOT Optical Transient (LVG GCN 21733) ~ 1 day before its detection. No OT detected brighter 19.1. Date UT Tstart -Ttrig Exp Type Limit 2017-08-26 05:13:29 0.708 day 180 Inspect 19.1 This message can be citted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21752 SUBJECT: LIGO/Virgo G299232: PIRATE observations of MASTER OT J033744.97+723159.0 DATE: 17/08/29 16:27:50 GMT FROM: Dean Roberts at PIRATE D. Roberts, U. Kolb & M.Morrell (The Open University) reporting on behalf of the PIRATE group: We observed the field of MASTER OT J033744.97+723159.0 (Lipunov et al., GCN Circ. 21719) with our 0.43m robotic telescope at Teide Observatory, Tenerife, Spain. Observations were taken at two epochs between 2017-08-28T23:51 to 2017-08-29T00:27 and 2017-08-29T03:33 to 2017-08-29T04:09. In total 12 images were taken in the Baader B filter and 12 images in the Baader R filter ranging between 100s-300s in exposure time. We detect the OT identified by MASTER (Lipunov et al.) at: 03h 37m 44.97s +72d 31m 59.0s. Our estimated magnitudes are: R = 16.49 +/- 0.06 B = 17.11 +/- 0.11 These magnitudes are not corrected for Galactic extinction in the direction of the OT. Further observations are ongoing in conjunction with our own transient search of the LIGO/Virgo bayestar-HLV skymap. -- The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England & Wales and a charity registered in Scotland (SC 038302). The Open University is authorised and regulated by the Financial Conduct Authority in relation to its secondary activity of credit broking. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21754 SUBJECT: LIGO/Virgo G299232: observations of the optical Transient Discovered by Swift/UVOT DATE: 17/08/29 18:57:50 GMT FROM: Alexei Pozanenko at IKI,Moscow A. Pozanenko (IKI), A. Volnova (IKI), I. Reva (AFIF), E. Mazaeva (IKI), P. Minaev (IKI), M. Krugov (AFIF) report on behalf of IKI-GW follow-up collaboration: We observed the field of the Optical Transient discovered by Swift/UVOT (Emery et al., GCN 21733) with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on 2017-08-28 (UT) 18:54:36. We obtained several images in R-filter. The optical transient (Emery et al., GCN 21733) is not detected in a combined image. Preliminary photometry of the afterglow is following. Date UT start t-T0 Filter Exp. OT Err. UL (Since LVC,mid, days) (s) (3 sigma) 2017-08-28 18:54:36 3.24609 R 8*180 n/d n/d 20.8 Photometry is based on nearby USNO-B1.0 stars (R2 magnitudes). The nearest galaxy (SDSS J014008.25+343414.8) to the transient position in coordinates (J2000) 01 40 08.247 +34 34 14.43 +/- 0.25" is marginally detected. The galaxy is at a distance of 11.5 arcsec from the transient position. The galaxy photometry is R=21.45 +/- 0.45. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21755 SUBJECT: LIGO/Virgo G299232: Liverpool Telescope observations DATE: 17/08/29 20:27:45 GMT FROM: Chris Copperwheat at LJMU ArI C.M.Copperwheat (LJMU) and I.A.Steele (LJMU) report on behalf of D.Bersier (LJMU), M.Bode (LJMU), C.Collins (LJMU), M.Darnley (LJMU), D.Galloway (Monash), A.Gomboc (Nova Gorica), S.Kobayashi (LJMU), A. Levan (Warwick), P.Mazzali (LJMU), C.Mundell (Bath), D.Perley (LJMU), E.Pian (Pisa), A.S. Piascik (LJMU), D. Pollacco (Warwick), D. Steeghs (Warwick), N.Tanvir (Leicester), K. Ulaczyk (Warwick), K.Wiersema (Leicester) and the GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration. --- We observed MASTER OTJ033744.97+723159.0, originally reported in GCN #21720, on 2017-08-29 at 04:05UT using the SPRAT spectrograph on the Liverpool Telescope. We concur with the classification reported in GCN #21737: using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) with the redshift of NGC1343 we believe this transient to be a supernova Type IIb at 2 days before maximum. We also observed the field of the optical transient discovered with Swift/UVOT (GCN #21733) in ugriz with the IO:O imager on the Liverpool Telescope, starting at 03:31UT on 2017-08-29. We do not detect an object at these coordinates, as has already been reported by a number of different groups. Our magnitude limits are comparable to those obtained with the Asiago 1.82 m Copernico Telescope (GCN #21745). ________________________________ Important Notice: the information in this email and any attachments is for the sole use of the intended recipient(s). If you are not an intended recipient, or a person responsible for delivering it to an intended recipient, you should delete it from your system immediately without disclosing its contents elsewhere and advise the sender by returning the email or by telephoning a number contained in the body of the email. No responsibility is accepted for loss or damage arising from viruses or changes made to this message after it was sent. The views contained in this email are those of the author and not necessarily those of Liverpool John Moores University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21756 SUBJECT: LIGO/Virgo G299232: WHT non-detection u-band optical transient DATE: 17/08/29 20:33:05 GMT FROM: Peter Jonker at SRON/RU P.G. Jonker (SRON/RU), M. Fraser (UCD), S. Nissanke (RU), R.P. Fender (Oxford), J. Broderick (ASTRON), A. Rowlinson (UvA, ASTRON), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester) report on behalf of the LOFAR Transients Key Science project: On Aug, 29, 2017, starting at 00:45 (UTC), we obtained a u'-band image with an exposure time of 300 sec, with the ACAM instrument mounted on the William Herschel Telescope on La Palma (Spain) of the optical transient reported by Emery et al. GCN21733 (see also Tomasella et al. GCN 21745). We do not detect a source at the reported position down to an SDSS-based AB limiting magnitude of u'>24.5 based on the faintest sources visible in the field. This implies a fading of more than a factor 350 in about 36.75 hours (assuming the time unit in GCN 21733 is UT). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21757 SUBJECT: LIGO/Virgo G299232 : RATIR Optical and NIR Observations of Swift UVOT source DATE: 17/08/29 21:43:33 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), V. Zach Golkhou (University of Washington), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Eleonora Troja (GSFC), and Carlos Román-Zúñiga (UNAM) report: We observed the field of Swift UVOT source (Emery et al., GCN 21733) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2017/08 29.24 to 2017/08 29.50 UTC (4 days after GW trigger G299232), obtaining a total 1.8 hours exposure in the g and r bands, 3.7 hours exposure in the i band, and 1.6 hours exposure in the Z, Y, J, and H bands. For a source within the UVOT error circle, in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following upper limits (3-sigma): g > 24.32 r > 24.09 i > 24.35 Z > 23.07 Y > 22.77 J > 22.41 H > 22.04 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21758 SUBJECT: LIGO/Virgo G299232: Further Swift/UVOT Observations of Optical Transient SwiftJ014008.5+343403.6 DATE: 17/08/29 22:55:12 GMT FROM: Samuel Emery at UCL-MSSL/Swift S.W.K. Emery (UCL-MSSL), A.A. Breeveld (UCL-MSSL), F.E. Marshall (NASA/GSFC), S.R. Oates (Uni. of Warwick), N.P.M. Kuin (UCL-MSSL), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester), D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G. Cusumano(INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V.D'Elia(ASDC), P.A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU), J.A. Kennea (PSU), H.A. Krimm (CRESST/GSFC/USRA), A.Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), P.T. O'Brien (U. Leicester), J.P. Osborne (U. Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU), E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team: Swift has performed follow-up ToO observations of the optical transient SwiftJ014008.5+343403.6, reported in Emery et al. (GCN 21733). We obtained 4 ks of data from 278 ks to 341 ks after the LVC trigger. This source has faded and is no longer detected in any filter. Earlier MASTER observations did not detect this source, see Lipunov et al. (GCN 21749). Other observatories have also not detected the source (Tomasella et al. (GCN 21745); Pozanenko et al. (GCN 21754); Copperwheat et al. (GCN 21755); Jonker et al. (GCN 21756); Butler et al. (GCN 21757)). We obtain preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373): Filter Start time Stop time Exposure(s) Magnitude(Vega) v T0+278 ks T0+341 ks 372 >20.1 b T0+277 ks T0+340 ks 372 >21.1 u T0+277 ks T0+340 ks 372 >20.7 uvw1 T0+276 ks T0+340 ks 745 >21.0 uvm2 T0+278 ks T0+341 ks 514 >20.5 uvw2 T0+277 ks T0+340 ks 1491 >21.6 The magnitudes are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the source (Schlegel et al. 1998). Further Swift observations are planned. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21759 SUBJECT: LIGO/Virgo G299232: HAWC follow-up DATE: 17/08/30 02:03:26 GMT FROM: Israel Martinez-Castellanos at UMD/HAWC I. Martinez-Castellanos (University of Maryland, College Park) and A.J. Smith (University of Maryland, College Park) on behalf of the HAWC Collaboration: The HAWC Collaboration performed a follow-up of LIGO trigger G299232. At the time of the trigger the HAWC local zenith was oriented toward (α, δ) = (75.0°, 19.0°), so the LV contour had just set in our field of view and no prompt follow-up was possible. We searched for long time scale emission during the following transit. The observations ranged from T0+28ks to T0+87ks. In total 70% of the probability space was covered. There were no >5 sigma points observed. For a single transit, the 5 sigma sensitivity to a power law spectrum with a -2.5 index ranges from ~1.9e-11 >1TeV cm^-2 s^-1 (~1 Crab unit) at dec=-19 to about 10 times higher at the edge of our FOV (45˚ from zenith). At the point of the source reported by Swift/UVOT (RA=01h40m08.55s DEC=+34d34'03.6", LVC GCN 21733) we obtain an 95% confidence level upper limit for >1TeV assuming a -2.5 spectrum of 4.3e-12 cm^-2 s^-1. These observations were made from T0+62ks to T0+85ks. We found no significant excess on the error radius corresponding to the neutrino reported by IceCube (RA=28.2˚ DEC= 44.8˚, LVC GCN 21698). For the location of maximum excess in the error radius we obtain an 95% confidence level upper limit for >1TeV assuming a -2.5 spectrum of 2.8e-11 cm^-2 s^-1. These observations were made from T0+64ks to T0+86ks. HAWC is a TeV gamma ray water Cherenkov array located in the state of Puebla, Mexico. It is sensitive to the energy range ~0.5-100TeV, and monitors 2/3 of the sky every day with an instantaneous field-of-view of ~2 sr. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21762 SUBJECT: LIGO/Virgo G299232: SVOM/2.16-m Optical Telescope Observations of Swift UVOT Transient DATE: 17/08/30 09:25:32 GMT FROM: Chao Wu at NAOC X.M. Meng (NAOC), L.P. Xin (NAOC), S. Antier (LAL), C. Wu (NAOC), N. Leroy (LAL), X.H. Han (NAOC), J.Y. Wei (NAOC), L. Huang (NAOC), Y. Xu (NAOC), H.B. Cai (NAOC), J. Wang (NAOC), X.M. Lu (NAOC), Y.L. Qiu (NAOC), J.S. Deng (NAOC), L. Cao (NAOC), S. Wang (NAOC), L. Jia (NAOC), S.C. Zou (NAOC), S.F. Liu (NAOC), Q.C. Feng (NAOC), H.L. Li (NAOC), D.W. Xu (NAOC), Y.J. Xiao (NAOC), W.L. Dong (NAOC), Y.T. Zheng (NAOC), E.W.Liang (GXU), X.G.Wang (GXU), Y.G. Yang (HBNU), B. Cordier (CEA), S.N. Zhang (NAOC), D. Dornic (CPPM), B.B. Wu (IHEP), D. Turpin (IRAP), A. Klotz (IRAP), C.Lachaud (APC), on behalf of the SVOM Gravitational Astronomy group report: We made a follow-up observation for the reported source in Emery et al. (GCN 21733) at 2017-08-29 at 18:40:30 UTC, with the BFOSC (Beijing Faint Object Spectrograph and Camera) on the 2.16-m telescope at Xinglong Observatory, China. No new source was detected in the stacked image with an total exposure time of 2*600 sec, down to an upper limit of R~22 mag for 3 sigma, calibrated to the nearby SDSS DR9 r magnitudes. Our results are consistent with the previous reports by Tomasella et al. (GCN 21745); Pozanenko et al. (GCN 21754); Copperwheat et al. (GCN 21755); Jonker et al. (GCN 21756); Butler et al. (GCN 21757), Emery et al., (21758) that the source was fading greatly, compared to the brightness reported in Emery et al. (GCN 21733) . We thank the staff of 2.16m telescope in Xinglong observatory, especially Huijuan Wang and Feng Xiao. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21766 SUBJECT: LIGO/Virgo G299232: GRAWITA Campo Imperatore optical observations DATE: 17/08/30 12:15:54 GMT FROM: Enzo Brocato at INAF-OA Roma A. Giunta, A. Di Paola, M. Centrone, N. Napoleone (INAF-OAR), G. Greco (Urbino University/INFN Firenze), M. Branchesi (GSSI), L. Amati (INAF-IASF Bo), L. A. Antonelli, (INAF-OAR), S. Ascenzi (INAF-OAR), S. Benetti (INAF-OAPD), M.T. Botticella (INAF-OAC),S. Campana (INAF-OAB), E. Cappellaro (INAF-OAPD), S. Covino, P. D’Avanzo (INAF-OAB), V. D'Elia (INAF-ASDC), F. Getman (INAF-OAC), A. Grado (INAF-OAC), L. Limatola (INAF-OAC), M. Lisi (INAF-OAR),A. Melandri (INAF-OAB), L. Nicastro, E. Palazzi, E. Pian (INAF-IASF Bo), S. Piranomonte (INAF-OAR), L. Pulone (INAF-OAR), A. Rossi (INAF-IASF Bo), G. Stratta (Urbino University/INFN Firenze), G. Tagliaferri (INAF-OAB), V. Testa (INAF-OAR), L . Tomasella (INAF-OAPD), S. Yang (INAF-OAPD) and E. Brocato (INAF-OAR) on behalf of GRAvitational Wave Inaf TeAm (GRAWITA) report: We carried out observa <>tions of LIGO/Virgo G299232 (LVC, GCN 21693) starting 6.7 hours after the trigger with the 0.9m/0.6m Schmidt telescope located at the Campo Imperatore Observatory (Italy). The observations were taken in the r-sloan band on 2017-08-25 and 2017-08-26 starting respectively at 19:55:57 UT and 20:15:21 UT with relatively good sky conditions. Each night the covered area of ~60 square degrees captured a containment probability of ~7,2% of the cWB map (LVC, GCN 21693). The area is divided in 5 blocks of 3x3 pointings, each pointing covering 1.15x1.15 square degrees of the sky with 3x120 sec exposure time. The pointing sequence was generated using the GWsky script (https://github.com/ggreco77/GWsky ) starting from the high probability region of the bayestar skymap and taking into account the airmass and relative density of nearby galaxies. The first block covers an area where GW skymap overlaps neutrino detection. The 3x3 square degrees pointing blocks are centered on the following coordinates RA, Dec (J2000) and UT times: 1 28.27 44.81 2017-08-25T20:32:06 2017-08-26T20:52:17 2 31.87 40.28 2017-08-25T21:53:52 2017-08-26T22:15:13 3 30.22 37.12 2017-08-25T23:14:13 2017-08-26T23:38:52 4 33.39 43.42 2017-08-26T01:41:21 2017-08-27T01:09:37 5 34.08 46.50 2017-08-26T02:44:46 2017-08-27T02:46:04 The limiting magnitude is r ~20.0-22.0 as a function of the observing conditions. Analysis of the images is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21769 SUBJECT: LIGO/Virgo G299232 ANTARES search (2) DATE: 17/08/30 16:09:41 GMT FROM: Damien Dornic at CPPM/CNRS M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (IFIC & APC), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite Paris Diderot), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration: GCN #21696 reported the ANTARES search for upward going High Energy Neutrinos from LIGO/Virgo G299232 event, for which only 42% of the initial 90% C.L contour map was visible (with upward going events). We report here on a dedicated analysis looking for down-going neutrino candidates in the on-line ANTARES data stream. Cuts on the quality of the track reconstruction and an energy proxy have been used to reduce the false alarm rate in such a way that one event matching in time (+/- 500 s) and direction (90% C.L contour) with G299232 would result in a 3-sigma excess. The ANTARES visibility, for down-going events, at the time of the alert together with the 90% contour of the probability map are shown in: https://www.cppm.in2p3.fr/~dornic/events/G299232/250817_down.png (gwantares/GW@ANT51) No down-going muon neutrino candidate events were recorded by ANTARES within the 90% C.L. contour and during a ± 500 s time-window centered on the G299232 event time. An extended search during ± 1 hour yields no coincidence. ANTARES, being installed in the Mediterranean Deep Sea, is the largest neutrino detector in the Northern Hemisphere. It is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is below 0.5 degrees. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21771 SUBJECT: LIGO/Virgo G299232: continued WHT observations of the field of SwiftJ014008.5+343403.6 DATE: 17/08/30 23:16:52 GMT FROM: Peter Jonker at SRON/RU LIGO/Virgo G299232: continued WHT observations of the field of SwiftJ014008.5+343403.6 P.G. Jonker (SRON/RU), M. Fraser (UCD), S. Nissanke (RU), R.P. Fender (Oxford), J. Broderick (ASTRON), A. Rowlinson (UvA, ASTRON), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester) report on behalf of the LOFAR Transients Key Science project: On Aug, 30, 2017, starting at 04:54 (UTC), we obtained r',i', and z'-band images with an exposure time of 3x600, 600, and 600 sec, respectively, with the ACAM instrument mounted on the William Herschel Telescope on La Palma (Spain) of the optical transient reported by Emery et al. GCN21733. Seeing conditions were mediocre with values as large as 2". We do not detect a source at the reported position down to an SDSS-based AB limiting magnitude of r', i', z' > 23.5, 21.5, 20.3 based on the faintest sources detected in the field. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21772 SUBJECT: LIGO/Virgo G299232: GRAWITA Asiago optical observations DATE: 17/08/31 10:39:34 GMT FROM: Lina Tomasella at INAF/OAPd L. Tomasella, S. Benetti, E. Cappellaro (INAF-OAPD), G. Greco (Urbino University/INFN Firenze), L. Amati (INAF-IASF Bo), L. A. Antonelli, S. Ascenzi (INAF-OAR), M.T. Botticella (INAF-OAC), M. Branchesi (GSSI), S. Campana, S. Covino, P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-ASDC), D. Fugazza, F. Getman, A. Grado (INAF-OAC), L. Limatola (INAF-OAC), M. Lisi (INAF-OAR), A. Melandri (INAF-OAB), L. Nicastro, E. Palazzi, E. Pian (INAF-IASF Bo), S. Piranomonte, L. Pulone (INAF-OAR), A. Rossi (INAF-IASF Bo), P. Schipani (INAF-OAC), G. Stratta (Urbino University/INFN Firenze), G. Tagliaferri (INAF-OAB), V. Testa (INAF-OAR), S. Yang (INAF-OAPD), E. Brocato (INAF-OAR) on behalf of GRavitational Wave Inaf TeAm report: We carried out follow up observations of LIGO/Virgo G299232 (LVC, GCN 21693) with the Schmidt 67/92 telescope located at Cima Ekar (Asiago, Italy). Sloan gr-bands images were taken on 2017-08-26 starting from UT 00:10:21. The pointing sequence was generated using the GWskyscript (https://github.com/ggreco77/GWsky) starting from the high probability region of the bayestar skymap and taking into account the airmass and relative density of nearby galaxies. Each pointing covers 1x1 square degrees of the sky with 3x180 sec exposure time per band. The pointing blocks are centered on the following coordinates RA, Dec (J2000) and UT starting times of exposures: a. 36.76037 +61.84232 2017-08-26T00:06:58 b. 41.81579 +63.26814 2017-08-26T00:47:35 c. 28.76182 +34.24004 2017-08-26T01:15:13 d. 29.34192 +32.22710 2017-08-26T01:41:33 e. 25.77839 +32.19475 2017-08-26T02:06:24 f. 28.89056 +30.76806 2017-08-26T02:30:09 The single exposure is characterised by an AB limiting magnitude of r > 22. We also observed with the Copernico 1.82m telescope (Cima Ekar, Asiago, Italy) and equipped with AFOSC instrument. Sloan g and r-bands images (FOV = 8.8 X 8.8 arcmin) were taken on 2017-08-26 starting from UT 00:18:10 either of seven nearby galaxies whose location on the sky and distance falls in the 90% volume reported by the BAYESTAR probability sky map (Singer et al. 2016) and listed by Cook et al. 2017 in GCN n. 21707 (pointing 1-7), and generated using the GWskyscript (https://github.com/ggreco77/GWsky; pointing 8-11): 1. IC 1695 2017-08-26T01:44:39 2. UGC01400 2017-08-26T01:53:39 3. UGC00774 2017-08-26T01:59:13 4. IC0260 2017-08-26T02:07:20 5. NGC0326 2017-08-26T02:13:02 6. SDSS J014929.88+123032.4 2017-08-26T02:18:27 7. MRK 0567 2017-08-26T02:30:00 8. 27.83787 +33.058979 2017-08-26T00:15:07 9. 30.54151 +52.365807 2017-08-26T00:29:12 10. 24.86730 +18.979811 2017-08-26T01:04:49 11. 28.69988 +31.314634 2017-08-26T01:29:22 Preliminary analysis do not show new transients in these fields. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21780 SUBJECT: LIGO/Virgo G299232: XSNAOC spectral observation of MASTER OTJ033744.97+723159.0 DATE: 17/08/31 20:24:41 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs Liming Rui (Tsinghua University), Xiaofeng Wang (Tsinghua university), Danfeng Xiang (Tsinghua Univeristy), Han Lin (Tsinghua Unviersity), and Huijuan Wang (NAOC) We obtained an optical spectrum (range 380-870 nm) of MASTER OTJ033744.97+723159.0 (Lipunov et al. GCN 21720, GCN2136), on 2017-08-29.54UT with the 2.16-m telescope at Xinglong Station of National Astronomical Observatories of China (NAOC) on BFOSC (Beijing Faint Object Spectrograph and Camera). The spectrum is consistent with a type IIb supernova a few days before the maximum light, using SN96cb data as the spectral templates. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21782 SUBJECT: LIGO/Virgo G299232/PGWB170825.55: MASTER archive images of the SIWFT/UVOT and MASTER OT J033744.97+723159.0 in NGC1343 galaxy before 25 DATE: 17/09/01 07:49:22 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.M.Lipunov, E. Gorbovskoy, V.G.Kornilov, N.Tyurina, V.Shumkov, D.Kuvshinov, P.Balanutsa, O.Gress, A.Kuznetsov, M.I.Panchenko, A.V.Krylov, I.Gorbunov, Lomonosov Moscow State University, Sternberg Astronomical Institute R. Rebolo, M. Serra-Ricart, G. Israelian, N.Lodiu The Instituto de Astrofisica de Canarias V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk N.M. Budnev, O. Gress, K. Ivanov, S.Yazev, Yu. Ishmuhamedova-Rabinovich, Irkutsk State University A. Tlatov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory R.Podesta, C.Lopez, F.Podesta Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina H.Levato, C.Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina D.Buckley, S.Potter, M.Kotze, South African Astronomical Observatory Analyzing MASTER database archive images of MASTER OT J033744.97+723159.0 (Lipunov et al. GCN 21720, GCN2136) we found 1 image on 2017-08-19 22:32:24.443 with clearly seen OT with unfiltered m_OT=18.6 . During Fermi GBM trigger 521687456 inspection MASTER-Kislovodsk observed the area RA(2000)=(18.200 +29.540) +-5.25deg GRB_error (statistical only) on 2017-07-14 22:54:12UT with mlim=18.7 . There is SIWFT/UVOT source (Emery et al., LVC GCN 21733, 21758) from LIGO/VIRGO G299232 error-box (Siellez et al., GCN 21693) with m_OT~18.7 on 2017-07-14 22:54:12UT The archival image is available at: http://master.sai.msu.ru/static/OT/MASTERKislovodsk20170714.jpg We are gratiful all follow up photometry (Im et al. GCN21723; Im et al. GCN21738; Butler et al. GCN21742, Roberts et al. GCN 21752) and spectral (Jonker et al. GCN 21737; Roberts et al. GCN 21752; Copperwheat et al. GCN21755; Liming Rui et al. GCN 21780) observations. This SN IIb is placed very far from NGC 1343 galaxy center at distance ~20 kpc. The massive star progenitor in the no star formation area is very strange. This message can be citted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21802 SUBJECT: LIGO/Virgo G299232: RoboPol observations of MASTER OT J033744.97+723159.0 DATE: 17/09/04 00:48:18 GMT FROM: Timothy Pearson at OVRO/Caltech P. Reig (U. of Crete/FORTH) & G.V. Panopoulou (Caltech) reporting on behalf of the RoboPol collaboration: We observed the optical transient OTJ033744.97+723159.0 (Lipunov et al. GCN 21720, GCN 21736), on 2017-08-29.07UT with the RoboPol polarimeter at the Skinakas observatory 1.3-m telescope. Preliminary analysis shows that the R-band fractional polarization of the source is 1.8+-0.47%. It is consistent with polarization of nearby field stars. Further observations are scheduled. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21809 SUBJECT: LIGO/Virgo G299232: LOFAR follow-up DATE: 17/09/04 15:24:30 GMT FROM: Peter Jonker at SRON/RU J.W. Broderick (ASTRON), A. Rowlinson (UvA, ASTRON), P.G. Jonker (SRON, RU), R.P. Fender (Oxford), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester), S. ter Veen (ASTRON), S. Nissanke (RU), A. Shulevski (ASTRON) report on behalf of the LOFAR Transients Key Science Project From 2017 August 30 - September 4, we observed a large fraction of the localisation error range of the Advanced LIGO/Virgo trigger G299232 (LVC, GCN 21693) with the ILT (International Low-Frequency Array [LOFAR] Telescope). The observations were obtained with the high-band antennas (HBA) at a centre frequency of 145 MHz (bandwidth 15.8 MHz). We used 6 simultaneous beams on the sky, where each beam has a field of view of approximately 12 deg^2 (beam FWHM 3.9 deg). The observations cover roughly 300 deg^2 in total at optimum sensitivity. Each field was observed for 225 min using a number of separate 25-min snapshots. The beam centres are given below (RA and Dec in degrees); the Bayestar-HLV localisation was used as a basis for calculating the coordinates of the beams. Two beams in separate pointings were centred on the IceCube neutrino candidate at RA = 28.2 deg, Dec = 44.8 deg (Bartos et al., GCN 21694; Bartos et al., GCN 21698). Furthermore, one beam was centred on the optical transient discovered by Swift/UVOT at RA = 25.035625 deg, Dec = 34.567667 deg (Emery et al., GCN 21733). Analysis is ongoing. We thank the ASTRON Radio Observatory for promptly scheduling the observations. Pointing 1 (integration time 225 min over the period 2017-08-30 23:00 UTC - 2017-08-31 06:21 UTC) 1) 34.039151 46.299866 2) 35.248501 48.949799 3) 28.200000 44.800000 4) 31.322127 48.348415 5) 36.756176 44.251317 6) 37.965526 46.901250 Pointing 2 (integration time 225 min over the period 2017-08-30 23:26 UTC - 2017-08-31 06:47 UTC) 1) 35.780064 51.725205 2) 36.750925 54.437875 3) 31.502071 50.889684 4) 32.472933 53.602354 5) 39.087195 49.848056 6) 40.058057 52.560726 Pointing 3 (integration time 225 min over the period 2017-08-31 23:00 UTC - 2017-09-01 06:21 UTC) 1) 29.306644 35.778068 2) 30.478008 38.389034 3) 25.035625 34.567667 4) 27.105198 37.906547 5) 31.508089 33.649589 6) 32.679454 36.260555 Pointing 4 (integration time 225 min over the period 2017-08-31 23:26 UTC - 2017-09-01 06:47 UTC) 1) 31.825000 41.000000 2) 33.084178 43.610966 3) 28.199341 40.517513 4) 28.200000 44.800000 5) 34.191481 38.871521 6) 35.450659 41.482487 Pointing 5 (integration time 225 min over the period 2017-09-03 01:00-08:21 UTC) 1) 41.738945 68.095823 2) 43.350996 70.808493 3) 34.635623 67.260303 4) 36.247674 69.972972 5) 47.230217 66.218674 6) 48.842268 68.931344 Pointing 6 (integration time 225 min over the period 2017-09-03 01:26-08:47 UTC) 1) 44.937500 79.572222 2) 44.267884 76.796335 3) 31.320689 78.289239 4) 31.990306 81.065126 5) 57.884694 78.079318 6) 58.554311 80.855205 Pointing 7 (integration time 225 min over the period 2017-09-04 00:00-07:21 UTC) 1) 37.337896 57.197845 2) 38.228521 59.934164 3) 32.518303 56.247531 4) 33.408928 58.983851 5) 41.266865 55.411839 6) 42.157490 58.148159 Pointing 8 (integration time 225 min over the period 2017-09-04 00:26-07:47 UTC) 1) 39.119146 62.670484 2) 40.170071 65.406804 3) 33.432096 61.720170 4) 34.483021 64.456490 5) 43.755272 60.884478 6) 44.806196 63.620798 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21811 SUBJECT: LIGO/Virgo G299232: Maidanak observations of optical transient SwiftJ014008.5+343403.6 DATE: 17/09/04 16:37:50 GMT FROM: Alexei Pozanenko at IKI,Moscow A. Pozanenko (IKI), A. Volnova (IKI), E. Mazaeva (IKI), B. Hafizov (UBAI), O. Burhonov (UBAI) report on behalf of IKI-GW follow-up collaboration: We observed the field of the Optical Transient discovered by Swift/UVOT (Emery et al., GCN 21733) with AZT-22 telescope of Maidanak observatory starting on 2017-08-28 (UT) 21:25:37. We obtained several images in R-filter. The optical transient (Emery et al., GCN 21733) is not detected in a combined image. Preliminary photometry of the field is following. Date UT start t-T0 Filter Exp. OT Err. UL (Since LVC,mid, days) (s) (3 sigma) 2017-08-28 21:25:37 3.34167 R 3600 n/d n/d 23.0 Photometry is based on nearby USNO-B1.0 stars (R2 magnitudes). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21819 SUBJECT: LIGO/Virgo G299232: Lulin Observations of Possible OTs DATE: 17/09/05 14:05:47 GMT FROM: Mansi M. Kasliwal at Caltech Po-Chieh Yu (NCU), C.-C. Ngeow (NCU), W.-H. Ip (NCU), Albert Kong (NTHU) on behalf of the GROWTH (Global Relay of Observatories Watching Transients Happen collaboration) We observed the possible OTs for LIGO/Virgo G299232, one at/near NGC 1343 (MASTER OT J033744.97+723159.0; GCN 21719), and the other one discovered by SWIFT/UVOT (GCN 21733) with Lulin One-meter Telescope (LOT). We detected OT J033744.97+723159.0 and calibrated with respect to the APASS catalog. Summary of the observations: 20170828 20:05:45 UT B 360s 17.32 +/- 0.01 20170828 20:00:15 UT V 300s 16.48 +/- 0.01 20170829 19:46:14 UT B 360s 17.19 +/- 0.01 20170829 19:52:30 UT V 300s 16.33 +/- 0.01 These magnitudes are on the Vega system and are not corrected for Galactic extinction in the direction of the OT. The second OT was observed once and we did not have any detection at the reported location (which confirms the follow-up announcements in GCN 21754 and 21757). We thank the staff of the Lulin observatory in Taiwan. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21844 SUBJECT: LIGO/Virgo G299232: Swift-XRT sources DATE: 17/09/07 13:12:46 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), J.A. Kennea (PSU), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester), A.A. Breeveld (UCL-MSSL), D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V.D'Elia(ASDC), S.W.K. Emery (UCL-MSSL), P. Giommi (ASI), C. Gronwall (PSU), H.A. Krimm (CRESST/GSFC/USRA), N.P.M. Kuin (UCL-MSSL), A.Y. Lien (GSFC/UMBC), F.E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), S.R. Oates (U. Warwick), P.T. O'Brien (U. Leicester), J.P. Osborne (U. Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU), E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team: Swift has performed a series of 768 observations, covering 653 separate locations within the LVC error region for the GW trigger G299232 convolved with the 2MPZ catalogue (Bilicki et al. 2014, ApJS, 210, 9), using the 'bayestar-HLV' GW localisation map. As this is a 3D skymap, galaxy distances were taken into account in selecting which ones to observe. The observations currently span from 11 ks to 758 ks after the LVC trigger, and cover 75.9 sq degrees on the sky (corrected for overlaps). This covers 8.3% of the probability in the 'bayestar-HLV' skymap, and 15% after convolving with the 2MPZ galaxy catalogue, as described by Evans et al., (2016, MNRAS, 462, 1591). A list of all observations and exposure times is in GraceDB. In total, we have detected 51 X-ray sources. Each source is assigned a rank of 1-4 which describes how likely it is to be related to the GW trigger, with 1 being the most likely and 4 being the least likely. The ranks are described at http://www.swift.ac.uk/ranks.php. We have found: * 0 sources of rank 1 * 1 source of rank 2 * 30 sources of rank 3 * 20 sources of rank 4 For all flux conversions and comparisons with catalogues and upper limits from other missions, we assumed a power-law spectrum with NH=3e20 cm^2, and photon index (Gamma)=1.7 RANK 2 source ============= This is a catalogued X-ray source which was detected at a level well above the catalogued flux. However, this is an RS CVn variable star, so this is not surprising. We do not consider this the counterpart. Source 11: ============= RA: 26.7914 ( = 01h 47m 9.94s) J2000 Dec: +23.7585 ( = +23d 45' 30.6") J2000 Error: +4.1 (arcsec, radius, 90% confidence). Peak Rate: 7.6e-02 +/- 1.5e-02 ct/sec (0.3-10 keV) Peak Flux: 3.3e-12 +/- 6.3e-13 erg cm^-2 s^-1 (0.3-10 keV) Catalogued: Yes Cat Source: 1RXS J014709.9+234529 in the ROSAT/RASSFSC catalogue Separation: 1.7" from the XRT source Cat Rate: 2.6e-02 +/- 1.1e-02 ct/sec Cat Flux: 7.3e-13 +/- 3.0e-13 erg cm^-2 s^-1 (0.3-10 keV) so the source is 3.6-sigma above the catalogued flux. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `V* BE Ari' is 4.1" away. There is 1 2MASS object within the source's 3-sigma error radius. RANK 3 sources ============== These are uncatalogued X-ray sources, however they are not brighter than previous upper limits, so do not stand out as likely counterparts to the GW trigger. Source 7: ============= RA: 28.8331 ( = 01h 55m 19.94s) J2000 Dec: +41.4501 ( = +41d 27' 00.4") J2000 Error: +6.1 (arcsec, radius, 90% confidence). Peak Rate: 2.0e-02 +/- 1.2e-02 ct/sec (0.3-10 keV) Peak Flux: 8.7e-13 +/- 5.3e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 3.7e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There is 1 GWGC or 2MPZ galaxy within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 8: ============= RA: 57.4297 ( = 03h 49m 43.13s) J2000 Dec: +75.2688 ( = +75d 16' 07.7") J2000 Error: +5.9 (arcsec, radius, 90% confidence). Peak Rate: 1.7e-02 +/- 7.3e-03 ct/sec (0.3-10 keV) Peak Flux: 7.4e-13 +/- 3.1e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.6e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 2 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 9: ============= RA: 26.4272 ( = 01h 45m 42.53s) J2000 Dec: +32.7277 ( = +32d 43' 39.7") J2000 Error: +6.8 (arcsec, radius, 90% confidence). Peak Rate: 2.8e-02 +/- 1.1e-02 ct/sec (0.3-10 keV) Peak Flux: 1.2e-12 +/- 4.6e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.2e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 13: ============= RA: 275.5870 ( = 18h 22m 20.88s) J2000 Dec: -24.5012 ( = -24d 30' 04.3") J2000 Error: +6.9 (arcsec, radius, 90% confidence). Peak Rate: 2.2e-02 +/- 9.4e-03 ct/sec (0.3-10 keV) Peak Flux: 9.6e-13 +/- 4.0e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 6.4e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `PMN J1822-2429' is 3.9" away. There are 3 2MASS objects within the source's 3-sigma error radius. Source 14: ============= RA: 280.4037 ( = 18h 41m 36.89s) J2000 Dec: -26.9052 ( = -26d 54' 18.7") J2000 Error: +6.5 (arcsec, radius, 90% confidence). Peak Rate: 1.3e-02 +/- 4.7e-03 ct/sec (0.3-10 keV) Peak Flux: 5.5e-13 +/- 2.0e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 4.3e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There are 2 2MASS objects within the source's 3-sigma error radius. Source 15: ============= RA: 30.5062 ( = 02h 02m 1.49s) J2000 Dec: +39.7221 ( = +39d 43' 19.6") J2000 Error: +7.5 (arcsec, radius, 90% confidence). Peak Rate: 1.7e-02 +/- 7.2e-03 ct/sec (0.3-10 keV) Peak Flux: 7.4e-13 +/- 3.1e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 4.2e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There is 1 GWGC or 2MPZ galaxy within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 16: ============= RA: 30.8523 ( = 02h 03m 24.55s) J2000 Dec: +39.8555 ( = +39d 51' 19.8") J2000 Error: +7.9 (arcsec, radius, 90% confidence). Peak Rate: 4.2e-02 +/- 3.1e-02 ct/sec (0.3-10 keV) Peak Flux: 1.8e-12 +/- 1.3e-12 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.4e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. The source may be fading, at the 1.2-sigma level. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 18: ============= RA: 277.0265 ( = 18h 28m 6.36s) J2000 Dec: -26.7567 ( = -26d 45' 24.1") J2000 Error: +6.0 (arcsec, radius, 90% confidence). Peak Rate: 2.5e-02 +/- 9.8e-03 ct/sec (0.3-10 keV) Peak Flux: 1.1e-12 +/- 4.2e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 6.3e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `HD 169938' is 3.5" away. There is 1 2MASS object within the source's 3-sigma error radius. Source 20: ============= RA: 21.1039 ( = 01h 24m 24.94s) J2000 Dec: +8.4009 ( = +08d 24' 03.2") J2000 Error: +5.2 (arcsec, radius, 90% confidence). Peak Rate: 3.3e-02 +/- 1.0e-02 ct/sec (0.3-10 keV) Peak Flux: 1.4e-12 +/- 4.3e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 4.7e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There is 1 GWGC or 2MPZ galaxy within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `2MASS J01242495+0824076' is 4.5" away. There is 1 2MASS object within the source's 3-sigma error radius. Source 23: ============= RA: 280.4462 ( = 18h 41m 47.09s) J2000 Dec: -31.1682 ( = -31d 10' 05.5") J2000 Error: +5.5 (arcsec, radius, 90% confidence). Peak Rate: 2.9e-02 +/- 9.7e-03 ct/sec (0.3-10 keV) Peak Flux: 1.2e-12 +/- 4.2e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 3.2e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 24: ============= RA: 280.4270 ( = 18h 41m 42.48s) J2000 Dec: -31.1927 ( = -31d 11' 33.7") J2000 Error: +4.6 (arcsec, radius, 90% confidence). Peak Rate: 5.0e-02 +/- 1.2e-02 ct/sec (0.3-10 keV) Peak Flux: 2.1e-12 +/- 5.1e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 3.5e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 25: ============= RA: 35.0606 ( = 02h 20m 14.54s) J2000 Dec: +50.7456 ( = +50d 44' 44.2") J2000 Error: +9.8 (arcsec, radius, 90% confidence). Peak Rate: 2.0e-02 +/- 7.8e-03 ct/sec (0.3-10 keV) Peak Flux: 8.6e-13 +/- 3.3e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.9e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There are 2 2MASS objects within the source's 3-sigma error radius. Source 27: ============= RA: 35.3623 ( = 02h 21m 26.95s) J2000 Dec: +51.4366 ( = +51d 26' 11.8") J2000 Error: +5.1 (arcsec, radius, 90% confidence). Peak Rate: 1.3e-02 +/- 4.6e-03 ct/sec (0.3-10 keV) Peak Flux: 5.4e-13 +/- 2.0e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 1.5e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 29: ============= RA: 20.0708 ( = 01h 20m 16.99s) J2000 Dec: +12.0556 ( = +12d 03' 20.2") J2000 Error: +6.1 (arcsec, radius, 90% confidence). Peak Rate: 1.3e-02 +/- 4.9e-03 ct/sec (0.3-10 keV) Peak Flux: 5.7e-13 +/- 2.1e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 9.8e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `NVSS J012016+120326' is 6" away. There is 1 2MASS object within the source's 3-sigma error radius. Source 30: ============= RA: 25.0723 ( = 01h 40m 17.35s) J2000 Dec: +23.4559 ( = +23d 27' 21.2") J2000 Error: +6.4 (arcsec, radius, 90% confidence). Peak Rate: 2.0e-02 +/- 7.8e-03 ct/sec (0.3-10 keV) Peak Flux: 8.6e-13 +/- 3.3e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 1.6e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `2MASS J01401722+2327211' is 1.6" away. There is 1 2MASS object within the source's 3-sigma error radius. Source 32: ============= RA: 29.7004 ( = 01h 58m 48.10s) J2000 Dec: +36.3610 ( = +36d 21' 39.6") J2000 Error: +5.1 (arcsec, radius, 90% confidence). Peak Rate: 2.4e-02 +/- 8.6e-03 ct/sec (0.3-10 keV) Peak Flux: 1.0e-12 +/- 3.7e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 3.6e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 3 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 34: ============= RA: 30.2909 ( = 02h 01m 9.82s) J2000 Dec: +44.1712 ( = +44d 10' 16.3") J2000 Error: +5.8 (arcsec, radius, 90% confidence). Peak Rate: 1.8e-02 +/- 7.7e-03 ct/sec (0.3-10 keV) Peak Flux: 7.9e-13 +/- 3.3e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 4.9e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 36: ============= RA: 30.1611 ( = 02h 00m 38.66s) J2000 Dec: +44.4550 ( = +44d 27' 18.0") J2000 Error: +5.7 (arcsec, radius, 90% confidence). Peak Rate: 1.3e-02 +/- 6.0e-03 ct/sec (0.3-10 keV) Peak Flux: 5.6e-13 +/- 2.6e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.8e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `4C 44.05' is 4.2" away. Source 41: ============= RA: 35.7720 ( = 02h 23m 5.28s) J2000 Dec: +43.5135 ( = +43d 30' 48.6") J2000 Error: +6.1 (arcsec, radius, 90% confidence). Peak Rate: 2.2e-02 +/- 7.5e-03 ct/sec (0.3-10 keV) Peak Flux: 9.4e-13 +/- 3.2e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 7.6e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 43: ============= RA: 25.0451 ( = 01h 40m 10.82s) J2000 Dec: +34.5945 ( = +34d 35' 40.2") J2000 Error: +7.6 (arcsec, radius, 90% confidence). Peak Rate: 4.3e-03 +/- 3.3e-03 ct/sec (0.3-10 keV) Peak Flux: 1.9e-13 +/- 1.4e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.4e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. The source may be fading, at the 0.3-sigma level. There are 3 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 44: ============= RA: 24.9350 ( = 01h 39m 44.40s) J2000 Dec: +34.6730 ( = +34d 40' 22.8") J2000 Error: +6.4 (arcsec, radius, 90% confidence). Peak Rate: 4.1e-03 +/- 2.6e-03 ct/sec (0.3-10 keV) Peak Flux: 1.8e-13 +/- 1.1e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.0e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. The source may be fading, at the 0.6-sigma level. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 45: ============= RA: 25.0033 ( = 01h 40m 0.79s) J2000 Dec: +34.5832 ( = +34d 34' 59.5") J2000 Error: +5.7 (arcsec, radius, 90% confidence). Peak Rate: 3.2e-03 +/- 1.7e-03 ct/sec (0.3-10 keV) Peak Flux: 1.4e-13 +/- 7.5e-14 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.5e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 3 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 46: ============= RA: 25.0002 ( = 01h 40m 0.05s) J2000 Dec: +34.6823 ( = +34d 40' 56.3") J2000 Error: +6.4 (arcsec, radius, 90% confidence). Peak Rate: 4.2e-03 +/- 2.0e-03 ct/sec (0.3-10 keV) Peak Flux: 1.8e-13 +/- 8.7e-14 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.0e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 2 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 47: ============= RA: 24.8943 ( = 01h 39m 34.63s) J2000 Dec: +34.4368 ( = +34d 26' 12.5") J2000 Error: +7.8 (arcsec, radius, 90% confidence). Peak Rate: 1.5e-02 +/- 1.7e-02 ct/sec (0.3-10 keV) Peak Flux: 6.4e-13 +/- 7.2e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 1.9e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. The source may be fading, at the 1.3-sigma level. There are 2 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 48: ============= RA: 25.1053 ( = 01h 40m 25.27s) J2000 Dec: +34.3855 ( = +34d 23' 07.8") J2000 Error: +6.9 (arcsec, radius, 90% confidence). Peak Rate: 6.8e-03 +/- 5.3e-03 ct/sec (0.3-10 keV) Peak Flux: 2.9e-13 +/- 2.3e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.8e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 2 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 49: ============= RA: 24.8491 ( = 01h 39m 23.78s) J2000 Dec: +34.5412 ( = +34d 32' 28.3") J2000 Error: +6.2 (arcsec, radius, 90% confidence). Peak Rate: 3.5e-03 +/- 1.9e-03 ct/sec (0.3-10 keV) Peak Flux: 1.5e-13 +/- 8.2e-14 erg cm^-2 s^-1 (0.3-10 keV) 1SXPS UL: 1.4e-03 ct/sec, (0.3-10 keV) so the source is 1.1-sigma above the 1SXPS 3-sigma upper limit. RASS UL: 3.4e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There is 1 GWGC or 2MPZ galaxy within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. A SIMBAD object `LAMOST J013923.93+343234.0' is 5.9" away. There is 1 2MASS object within the source's 3-sigma error radius. Source 50: ============= RA: 25.0324 ( = 01h 40m 7.78s) J2000 Dec: +34.6094 ( = +34d 36' 33.8") J2000 Error: +7.1 (arcsec, radius, 90% confidence). Peak Rate: 4.0e-03 +/- 4.6e-03 ct/sec (0.3-10 keV) Peak Flux: 1.7e-13 +/- 2.0e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.6e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 2 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. There is 1 2MASS object within the source's 3-sigma error radius. Source 51: ============= RA: 25.1025 ( = 01h 40m 24.60s) J2000 Dec: +34.5437 ( = +34d 32' 37.3") J2000 Error: +7.5 (arcsec, radius, 90% confidence). Peak Rate: 2.7e-03 +/- 2.2e-03 ct/sec (0.3-10 keV) Peak Flux: 1.2e-13 +/- 9.5e-14 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 1.8e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 3 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 52: ============= RA: 24.9789 ( = 01h 39m 54.94s) J2000 Dec: +34.6917 ( = +34d 41' 30.1") J2000 Error: +7.9 (arcsec, radius, 90% confidence). Peak Rate: 4.7e-03 +/- 2.9e-03 ct/sec (0.3-10 keV) Peak Flux: 2.0e-13 +/- 1.2e-13 erg cm^-2 s^-1 (0.3-10 keV) RASS UL: 2.5e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. There is no evidence for fading. There are 2 GWGC or 2MPZ galaxies within 200 kpc of the source. and consistent (within 3-sigma) with the distance to the GW object. Source 53: ============= RA: 24.8754 ( = 01h 39m 30.10s) J2000 Dec: +34.6003 ( = +34d 36' 01.1") J2000 Error: +8.4 (arcsec, radius, 90% confidence). Peak Rate: 2.1e-02 +/- 2.3e-02 ct/sec (0.3-10 keV) Peak Flux: 8.9e-13 +/- 1.0e-12 erg cm^-2 s^-1 (0.3-10 keV) 1SXPS UL: 1.4e-02 ct/sec, (0.3-10 keV) so the source is not above the 1SXPS 3-sigma upper limit. RASS UL: 2.1e-02 ct/sec, 3-sigma, converted to XRT (0.3-10 keV) so the source is not above the RASS 3-sigma upper limit. The source may be fading, at the 1.3-sigma level. NOTE: this source is NOT within 200 kpc of a GWGC or 2MPZ galaxy which is consistent (within 3-sigma) with the distance to the GW object. RANK 4 sources ============== These are catalogued X-ray sources, showing no signs of outburst compared to previous observations, so they are not likely to be related to the GW trigger. Therefore, we do not list details of the sources here. This circular is an official product of the Swift team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21867 SUBJECT: LIGO/Virgo G299232: Pierre Auger Observatory follow-up DATE: 17/09/12 08:02:10 GMT FROM: Jaime Alvarez-Muniz at Pierre Auger Observatory J. Alvarez-Muniz, F. Pedreira, E. Zas (Univ. Santiago de Compostela, Spain), K. H. Kampert & M. Schimp (Bergische Universitat, Wuppertal, Germany) on behalf of the Pierre Auger Collaboration. In response to the LIGO/Virgo GW trigger G299232 (GCN #21693, T0=2017-08-25, 13:13:37.983 UTC): We searched for Ultra High Energy (UHE) neutrinos with energies above ~ 1e17 eV in data collected with the Surface Detector (SD) of the Pierre Auger Observatory in a [-500,500] second interval about the LIGO-Virgo trigger G299232 as well as 1 day after it. NO events survived the cuts applied to reject the background due to UHE Cosmic Rays i.e. NO neutrino candidates were detected. The field of view (fov) where the SD of Auger is sensitive to UHE neutrinos (corresponding to inclined directions with respect to the vertical relative to the ground) was coincident with only a small fraction of the most updated LIGO 90% localization region (bayestar-HLV.fits.gz) at the time T0 of the merger alert. Some parts of the 90% region closest to the Northern hemisphere are never visible in the Auger fov. The Pierre Auger Observatory is an UHE Cosmic Ray detector located in the Mendoza Province in Argentina. It consists of an array of Water Cherenkov detectors spread over a total surface of 3000 km^2 arranged in a triangular grid of 1.5 km side as well as Fluorescence telescopes and other systems (see 10.1016/j.nima.2015.06.058 for more information). For neutrino searches from GW events with Auger, please refer to: https://journals.aps.org/prd/pdf/10.1103/PhysRevD.94.122007 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21870 SUBJECT: LIGO/Virgo G299232: Konus-Wind observations DATE: 17/09/12 14:32:43 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: Konus-Wind (KW) was observing the whole sky at the time of the LIGO/Virgo event G299232 (2017-08-25 13:13:37.977 UTC, hereafter T0; LIGO/Virgo Collaboration GCN Circ. 21693). No triggered KW event happened from ~4400 s before and ~0.8 days after T0. The closest waiting-mode event was ~0.2 days after T0. Using waiting-mode data within the interval T0 +/- 100 s, we found no significant (> 5 sigma) excess over the background in both KW detectors on temporal scales from 2.944 s to 100 s. We estimate an upper limit (90% conf.) on the 10 keV – 10 MeV fluence to 8.4x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a typical KW short GRB spectrum (an exponentially cut off power law with alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding limiting peak flux is 3.0x10^-7 erg/cm^2/s (10 keV - 10 MeV, 2.944 s scale). All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21875 SUBJECT: LIGO/Virgo G299232: Khureltogot observations DATE: 17/09/12 19:49:39 GMT FROM: Alexei Pozanenko at IKI,Moscow A. Pozanenko (IKI), E. Mazaeva (IKI), A. Volnova (IKI), S. Schmalz (KIAM), N. Tungalag (Research Center of Astronomy and Geophysics MAS), I. Molotov (KIAM) report on behalf of IKI-GW follow-up collaboration: We observed the field of LIGO/Virgo trigger G299232 (LVC GCN 21693) and the error circle of IceCube candidate X1, hereafter ICX1 (GCNs 21694, 21698) with wide FOV VT-78a telescope of Khureltogot observatory starting on 2017-08-25 (UT) 15:24:13. We obtained several unfiltered images with the two time series, each centered to the position of localization reported in GCN 21694, and GCN 21698, respectively. Preliminary results of our analysis of the fields are following. Date UT start t-T0 Exp. UL FOV Center Coverage (Since G299232 (s) (5 sigma) RA, Dec. % mid, days) degrees 2017-08-25 15:24:13 0.11289 60*60 19.3 27.1, 45.1 85.1 2017-08-25 16:32:52 0.16054 60*60 19.4 28.2, 44.8 78.3 Photometry is based on USNO-B1.0 stars (R2 magnitudes). Total coverage of the error region of ICX1 (GCN 21698) is 85.7%. The map of the coverage can be found at http://grb.rssi.ru/GW170825_G299232/LVC_IC_Khureltogot_v3.png We found no new or unknown objects in the combined images up to the limits listed above. We investigate all sources above S/N > 10 (~17m) and found no significant variability of the sources between the two epochs. We found no significantly more brighter sources which could be galaxies (including galaxy 2MASX J01571097+4715588 listed as Nearby Galaxies in the Localization Volume (GCN 21707)) than their R-magnitudes presented in the USNO-B1.0 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21938 SUBJECT: LIGO/Virgo G299232/GW170825: serendipitous XMM-Newton slew observations DATE: 17/09/27 20:43:48 GMT FROM: Eleonora Troja at GSFC/Swift A. M. Read (U. Leicester), A. Tiengo (IUSS Pavia), R. Salvaterra (INAF-IASF Milano), E. Troja (NASA/GSFC), and R. D. Saxton (ESAC) report: We analyzed the XMM-Newton slews made after the LIGO/Virgo G299232/ GW170825 event. The first two slews intercepting the GW localization map cover it for about 41.2 square degrees: Obs ID     |    date    |   T-T_GW   |coverage of localization map 9325000003 | 2017-09-07 |   12.7 d   |  8.0 deg2 9325100002 | 2017-09-09 |   14.7 d   |  33.2 deg2 For each dataset (EPIC pn data with the Medium filter) we performed the source detection following the method described in Troja et al. 2016 (ApJ, 822, L8). Typical sensitivity limits of slew observations are ~6e-13 ergs cm-2 s-1 in the 0.2-2 keV band and ~4e-12 ergs cm-2 s-1 in the 2-12 keV band. The list of the most significant 0.2-12 keV band detections (DET_ML>12) in each slew intersecting the GW170825 localization map, with no counterpart within 30 arcsec in the ROSAT All Sky Survey (Boller et al. 2016, A&A 588, A103) and with no X-ray sources with compatible position and flux detected in archival XMM-Newton observations, is reported below. The flux and counts are computed in the 0.2-12 keV energy band. Rank (1-4, 1 most likely, 4 least likely) indicates how likely the object is to be the GW counterpart. ---------- Revolution 3250, Observation ID 9325000003 RA (deg) DEC (deg) CTS  DET_ML EXPOSURE(s) FLUX(ergs cm-2 s-1) Rank 269.3143 -25.1624  24.1 12.1   4.9         4.9e-11 4,extended ---------- Revolution 3251, Observation ID 9325100002 RA (deg)  DEC (deg) CTS  DET_ML EXPOSURE(s) FLUX(ergs cm-2 s-1) Rank 243.0149  20.2417   4.2  17.3    7.1        6.0e-12             4 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21945 SUBJECT: LIGO/VIRGO G299232: AMI-LA Observations of the optical transient Swift J014008.5+343403.6 DATE: 17/10/01 17:00:59 GMT FROM: Kunal Mooley at U of Oxford K. P. Mooley (Hintze Fellow, Oxford) reports on behalf of a larger collaboration We observed the location of the Swift J014008.5+343403.6 (Emery et al., LVC GCNs 21733, 21758; discovered 1.95 days post-LVC trigger) with the AMI Large Array. Our observations at 15 GHz carried out on Aug 31.06, Sep 02.15 and Sep 08.12 UT (5.5d, 7.6d and 13.6d post-trigger respectively) do not reveal any radio afterglow associated with the optical transient, with 3sigma upper limits of 111 uJy, 160 uJy and 127 uJy. We thank the AMI-LA staff for scheduling these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21962 SUBJECT: LIGO/Virgo G299232: LOFAR follow-up DATE: 17/10/03 11:33:21 GMT FROM: Peter Jonker at SRON/RU J.W. Broderick (ASTRON), A. Rowlinson (UvA, ASTRON), P.G. Jonker (SRON, RU), R.P. Fender (Oxford), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester), S. ter Veen (ASTRON), S. Nissanke (RU), A. Shulevski (ASTRON) report on behalf of the LOFAR Transients Key Science Project From 2017 September 23-28, we observed a large fraction of the localisation region of the Advanced LIGO/Virgo trigger G299232 (LVC, GCN 21693) with the ILT (International Low-Frequency Array [LOFAR] Telescope). The observations were obtained with the high-band antennas (HBA) at a centre frequency of 145 MHz (bandwidth 15.8 MHz). We used 6 simultaneous beams on the sky, where each beam has a field of view of approximately 12 deg^2 (beam FWHM 3.9 deg). The observations cover roughly 300 deg^2 in total at optimum sensitivity. Each field was observed for 225 min using a number of separate 25-min snapshots. The beam centres are given below (RA and Dec in degrees); the Bayestar-HLV localisation was used as a basis for calculating the coordinates of the beams. The setup is identical to the previous set of LOFAR follow-up observations described in Broderick et al., GCN 21809. Two beams in separate pointings were centred on the IceCube neutrino candidate at RA = 28.2 deg, Dec = 44.8 deg (Bartos et al., GCN 21694; Bartos et al., GCN 21698). Furthermore, one beam was centred on the optical transient discovered by Swift/UVOT at RA = 25.035625 deg, Dec = 34.567667 deg (Emery et al., GCN 21733). Analysis is ongoing. We thank the ASTRON Radio Observatory for scheduling the observations. Pointing 1 (integration time 225 min over the period 2017-09-23 21:00 UTC - 2017-09-24 04:21 UTC) 1) 34.039151 46.299866 2) 35.248501 48.949799 3) 28.200000 44.800000 4) 31.322127 48.348415 5) 36.756176 44.251317 6) 37.965526 46.901250 Pointing 2 (integration time 225 min over the period 2017-09-23 21:26 UTC - 2017-09-24 04:47 UTC) 1) 35.780064 51.725205 2) 36.750925 54.437875 3) 31.502071 50.889684 4) 32.472933 53.602354 5) 39.087195 49.848056 6) 40.058057 52.560726 Pointing 3 (integration time 225 min over the period 2017-09-24 21:00 UTC - 2017-09-25 04:21 UTC) 1) 29.306644 35.778068 2) 30.478008 38.389034 3) 25.035625 34.567667 4) 27.105198 37.906547 5) 31.508089 33.649589 6) 32.679454 36.260555 Pointing 4 (integration time 225 min over the period 2017-09-24 21:26 UTC - 2017-09-25 04:47 UTC) 1) 31.825000 41.000000 2) 33.084178 43.610966 3) 28.199341 40.517513 4) 28.200000 44.800000 5) 34.191481 38.871521 6) 35.450659 41.482487 Pointing 5 (integration time 225 min over the period 2017-09-26 21:11 UTC - 2017-09-27 04:32 UTC) 1) 41.738945 68.095823 2) 43.350996 70.808493 3) 34.635623 67.260303 4) 36.247674 69.972972 5) 47.230217 66.218674 6) 48.842268 68.931344 Pointing 6 (integration time 225 min over the period 2017-09-26 21:37 UTC - 2017-09-27 04:58 UTC) 1) 44.937500 79.572222 2) 44.267884 76.796335 3) 31.320689 78.289239 4) 31.990306 81.065126 5) 57.884694 78.079318 6) 58.554311 80.855205 Pointing 7 (integration time 225 min over the period 2017-09-27 22:00 UTC - 2017-09-28 05:21 UTC) 1) 37.337896 57.197845 2) 38.228521 59.934164 3) 32.518303 56.247531 4) 33.408928 58.983851 5) 41.266865 55.411839 6) 42.157490 58.148159 Pointing 8 (integration time 225 min over the period 2017-09-27 22:26 UTC - 2017-09-28 05:47 UTC) 1) 39.119146 62.670484 2) 40.170071 65.406804 3) 33.432096 61.720170 4) 34.483021 64.456490 5) 43.755272 60.884478 6) 44.806196 63.620798 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21964 SUBJECT: LIGO/Virgo G299232: MAGIC Cherenkov Telescopes observations DATE: 17/10/03 13:25:13 GMT FROM: Antonio Stamerra at INAF-OATo/SNS-Pisa R. Mirzoyan on behalf of the MAGIC Collaboration In response to the LIGO/Virgo GW event G299232 (GCN 21693), the MAGIC Cherenkov Telescopes located at the Observatory El Roque de Los Muchachos of the Istituto de Astrofisica de Canarias (IAC) observed the following targets reported by follow-up observations: Target-1: the IceCube muon-1 region (GCN 21694 and GCN 21698); Target-2: the optical transient reported by MASTER OTJ033744.97+723159.0 (GCN 21719, GCN 21720, GCN 21736); Target-3: Swift-UVOT transient (GCN 21733). Target-1 ======= A scan of the region defined by the neutrino-muon detected by IceCube (RA: 28.2 deg DEC: 44.8 deg sigma: 3.8 deg, GCN 21698) was performed through four different pointings on August 26, between 03:03 and 05:28 UT Pointing-1: RA: +01h 52m 48.0s DEC: +44d 47m 60.0s; Effective observation time: 0.51 hr Pointing-2: RA: +01h 46m 24.0s DEC: +44d 47m 60.0s; Effective observation time: 0.57 hr Pointing-3: RA: +01h 49m 36.0s DEC: +46d 12m 00.0s; Effective observation time: 0.51 hr Pointing-4: RA: +01h 49m 36.0s DEC: +43d 12m 00.0s; Effective observation time: 0.51 hr corresponding to a region of ~10 deg^2, RA: ~26-29 deg DEC:~ 43-46 deg. Weather conditions were not ideal, with somewhat reduced transmission because of the Sahara dust in the atmosphere. A preliminary skymap was built. No excess is found. Very preliminary upper limits at E>200 GeV are ~1.5e-11 ph/cm2/s, valid only at the center of the field of view. Target-2 ======= MAGIC observed at the position of MASTER OTJ033744.97+723159.0, RA: 03h 37m 44.97s DEC: +72d 31m 59.0s (GCN 21719) on August 28, from 03:24 to 05:26 UT for 1.92 hrs effective time and on August 29, from 01:50 and 03:15 UT for 0.97 hrs effective time. Fair weather conditions, partially affected by dust and moderate atmospheric absorption. No significant excess was found. The preliminary upper limit on the flux at E>200 GeV is 5.5e-12 ph/cm2/s. Target-3 ======= MAGIC observed at the position of the unidentified transient detected by Swift/UVOT RA: 01h 40m 08.55s DEC: +34d 34m 03.6s (GCN 21733) on August 29 at 03:23 UT for 0.8 hrs effective time. Fair weather conditions, partially affected by dust and moderate atmospheric absorption. No significant excess was found. The preliminary upper limit on the flux at E>200 GeV is 2.1e-11 ph/cm2/s. ---------- MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located at the the Observatory El Roque de Los Muchachos of the Istituto de Astrofisica de Canarias (IAC), Spain and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 50 TeV, (https://magic.mpp.mpg.de). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21969 SUBJECT: LIGO/Virgo G299232: SWASP optical imaging coverage DATE: 17/10/04 15:25:10 GMT FROM: Danny Steeghs at U of Warwick/GOTO D.Steeghs, D.Pollacco, K.Ulaczyk, R.Cutter, R.West, A.Levan​, J.Lyman​, P.Chote, J.McCormac (U. Warwick) D.K.Galloway, E.Rol, E.Thrane​, K.Ackley, A.Casey​ (Monash U.) V.Dhillon, M.Dyer, S.Littlefair, E.Daw, J.Mullaney​, L.Makrygianni​, J.Maund (U. Sheffield) G.Ramsay (Armagh O.) P.O'Brien, R.Starling​, R.Eyles​ (U. Leicester) ​S.Poshyachinda, S.Aukkaravittayapun, U.Sawangwit, S.Awiphan, D.Mkrtichian (NARIT) On behalf of the GOTO collaboration: We report on optical observations with the SuperWASP Exoplanet camera array on La Palma, in response to G299232 (GCN #21693). Targeted observations containing approximately 50% of the total source location probability were performed between 23:24 UT 25/08/2017 and 05:52 UT 26/08/2017. This coverage is based on the bayestar-HLV skymap with combined Ligo/Virgo constraints and is focused on the northern hemisphere region of highest probability density. Each pointing consisted of 3x30s exposures in the clear filter and pointings were repeated between 38 and 50 times during that observing window. These regions were also observed the following night between 23:20 UT 26/08/2017 and 05:51 UT 27/08/2017. Observations at the same position were stacked and crossmatched with APASS for photometric calibration. Conditions were not fully stable and our 5-sigma limiting magnitudes in these stacks range from 15.9 to 17.1 (V-band equivalent). No new transients were identified in these data. We examined our ​images​ for ​evidence of the Swift/UVOT source ​J014008.5+343403.6 (GCN #21733)​. ​ Our stacks at this position reach V=17.0 and precede the SWIFT detection. A difference image analysis shows no evidence for a source at the reported position during either of our nights of data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22172 SUBJECT: LIGO/Virgo G299232: LOFAR follow-up DATE: 17/11/28 10:02:14 GMT FROM: Antonia Rowlinson at U van Amsterdam J.W. Broderick (ASTRON), K. Gourdji (UvA), A. Rowlinson (UvA, ASTRON), P.G. Jonker (SRON, RU), R.P. Fender (Oxford), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester), S. ter Veen (ASTRON), S. Nissanke (RU), A. Shulevski (ASTRON) report on behalf of the LOFAR Transients Key Science Project From 2017 November 18-26, we observed a large fraction of the localisation region of the Advanced LIGO/Virgo trigger G299232 (LVC, GCN 21693) with the ILT (International Low-Frequency Array [LOFAR] Telescope). The observations were obtained with the high-band antennas (HBA) at a centre frequency of 145 MHz (bandwidth 15.8 MHz). We used 6 simultaneous beams on the sky, where each beam has a field of view of approximately 12 deg^2 (beam FWHM 3.9 deg). The observations cover roughly 300 deg^2 in total at optimum sensitivity. Each field was observed for 225 min using a number of separate 25-min snapshots. The beam centres are given below (RA and Dec in degrees); the Bayestar-HLV localisation was used as a basis for calculating the coordinates of the beams. The setup is identical to the previous sets of LOFAR follow-up observations described in Broderick et al., GCN 21809 and GCN 21962. Two beams in separate pointings were centred on the IceCube neutrino candidate at RA = 28.2 deg, Dec = 44.8 deg (Bartos et al., GCN 21694; Bartos et al., GCN 21698). Furthermore, one beam was centred on the optical transient discovered by Swift/UVOT at RA = 25.035625 deg, Dec = 34.567667 deg (Emery et al., GCN 21733). Analysis is ongoing. We thank the ASTRON Radio Observatory for scheduling the observations. Pointing 1 (integration time 225 min over the period 2017-11-18 18:11 UTC - 2017-11-19 01:32 UTC) 1) 34.039151 46.299866 2) 35.248501 48.949799 3) 28.200000 44.800000 4) 31.322127 48.348415 5) 36.756176 44.251317 6) 37.965526 46.901250 Pointing 2 (integration time 225 min over the period 2017-11-18 18:37 UTC - 2017-11-19 01:58 UTC) 1) 35.780064 51.725205 2) 36.750925 54.437875 3) 31.502071 50.889684 4) 32.472933 53.602354 5) 39.087195 49.848056 6) 40.058057 52.560726 Pointing 3 (integration time 225 min over the period 2017-11-20 18:11 UTC - 2017-11-21 01:32 UTC) 1) 29.306644 35.778068 2) 30.478008 38.389034 3) 25.035625 34.567667 4) 27.105198 37.906547 5) 31.508089 33.649589 6) 32.679454 36.260555 Pointing 4 (integration time 225 min over the period 2017-11-20 18:37 UTC - 2017-11-21 01:58 UTC) 1) 31.825000 41.000000 2) 33.084178 43.610966 3) 28.199341 40.517513 4) 28.200000 44.800000 5) 34.191481 38.871521 6) 35.450659 41.482487 Pointing 5 (integration time 225 min over the period 2017-11-24 18:11 UTC - 2017-11-25 01:32 UTC) 1) 41.738945 68.095823 2) 43.350996 70.808493 3) 34.635623 67.260303 4) 36.247674 69.972972 5) 47.230217 66.218674 6) 48.842268 68.931344 Pointing 6 (integration time 225 min over the period 2017-11-24 18:37 UTC - 2017-11-25 01:58 UTC) 1) 44.937500 79.572222 2) 44.267884 76.796335 3) 31.320689 78.289239 4) 31.990306 81.065126 5) 57.884694 78.079318 6) 58.554311 80.855205 Pointing 7 (integration time 225 min over the period 2017-11-25 18:11 UTC - 2017-11-26 01:32 UTC) 1) 37.337896 57.197845 2) 38.228521 59.934164 3) 32.518303 56.247531 4) 33.408928 58.983851 5) 41.266865 55.411839 6) 42.157490 58.148159 Pointing 8 (integration time 225 min over the period 2017-11-25 18:37 UTC - 2017-11-26 01:58 UTC) 1) 39.119146 62.670484 2) 40.170071 65.406804 3) 33.432096 61.720170 4) 34.483021 64.456490 5) 43.755272 60.884478 6) 44.806196 63.620798 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22651 SUBJECT: LIGO/Virgo G299232: LOFAR follow-up DATE: 18/04/18 12:16:06 GMT FROM: Antonia Rowlinson at U van Amsterdam J.W. Broderick (ASTRON), K. Gourdji (UvA), A. Rowlinson (UvA, ASTRON), P.G. Jonker (SRON, RU), A.J. Stewart (SIfA), R.P. Fender (Oxford), R.A.M.J. Wijers (UvA), B.W. Stappers (Manchester), S. ter Veen (ASTRON), S. Nissanke (RU), A. Shulevski (UvA) report on behalf of the LOFAR Transients Key Science Project From 2018 April 7-15, we observed a large fraction of the localisation region of the Advanced LIGO/Virgo trigger G299232 (LVC, GCN 21693) with the ILT (International Low-Frequency Array [LOFAR] Telescope). The observations were obtained with the high-band antennas (HBA) at a centre frequency of 145 MHz (bandwidth 15.8 MHz). We used 6 simultaneous beams on the sky, where each beam has a field of view of approximately 12 deg^2 (beam FWHM 3.9 deg). The observations cover roughly 300 deg^2 in total at optimum sensitivity. Each field was observed for 245 min using a number of separate 25-min snapshots, as well as a single 20-min snapshot. The beam centres are given below (RA and Dec in degrees); the Bayestar-HLV localisation was used as a basis for calculating the coordinates of the beams. The pointing setup is identical to the previous sets of LOFAR follow-up observations described in Broderick et al., GCN 21809, GCN 21962 and GCN 22172. Two beams in separate pointings were centred on the IceCube neutrino candidate at RA = 28.2 deg, Dec = 44.8 deg (Bartos et al., GCN 21694; Bartos et al., GCN 21698). Furthermore, one beam was centred on the optical transient discovered by Swift/UVOT at RA = 25.035625 deg, Dec = 34.567667 deg (Emery et al., GCN 21733). Analysis is ongoing. We thank the ASTRON Radio Observatory for scheduling the observations. Pointing 1 (integration time 245 min over the period 2018-04-07 08:48 UTC - 2018-04-07 16:56 UTC) 1) 34.039151 46.299866 2) 35.248501 48.949799 3) 28.200000 44.800000 4) 31.322127 48.348415 5) 36.756176 44.251317 6) 37.965526 46.901250 Pointing 2 (integration time 245 min over the period 2018-04-07 08:27 UTC - 2018-04-07 16:35 UTC) 1) 35.780064 51.725205 2) 36.750925 54.437875 3) 31.502071 50.889684 4) 32.472933 53.602354 5) 39.087195 49.848056 6) 40.058057 52.560726 Pointing 3 (integration time 245 min over the period 2018-04-08 08:25 UTC - 2018-04-08 16:33 UTC) 1) 29.306644 35.778068 2) 30.478008 38.389034 3) 25.035625 34.567667 4) 27.105198 37.906547 5) 31.508089 33.649589 6) 32.679454 36.260555 Pointing 4 (integration time 245 min over the period 2018-04-08 08:04 UTC - 2018-04-08 16:12 UTC) 1) 31.825000 41.000000 2) 33.084178 43.610966 3) 28.199341 40.517513 4) 28.200000 44.800000 5) 34.191481 38.871521 6) 35.450659 41.482487 Pointing 5 (integration time 245 min over the period 2018-04-14 08:51 UTC - 2018-04-14 16:59 UTC) 1) 41.738945 68.095823 2) 43.350996 70.808493 3) 34.635623 67.260303 4) 36.247674 69.972972 5) 47.230217 66.218674 6) 48.842268 68.931344 Pointing 6 (integration time 245 min over the period 2018-04-14 08:30 UTC - 2018-04-14 16:38 UTC) 1) 44.937500 79.572222 2) 44.267884 76.796335 3) 31.320689 78.289239 4) 31.990306 81.065126 5) 57.884694 78.079318 6) 58.554311 80.855205 Pointing 7 (integration time 245 min over the period 2018-04-15 08:30 UTC - 2018-04-15 16:38 UTC) 1) 37.337896 57.197845 2) 38.228521 59.934164 3) 32.518303 56.247531 4) 33.408928 58.983851 5) 41.266865 55.411839 6) 42.157490 58.148159 Pointing 8 (integration time 245 min over the period 2018-04-15 08:09 UTC - 2018-04-15 16:17 UTC) 1) 39.119146 62.670484 2) 40.170071 65.406804 3) 33.432096 61.720170 4) 34.483021 64.456490 5) 43.755272 60.884478 6) 44.806196 63.620798