//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26903 SUBJECT: LIGO/Virgo S200128d: Global MASTER-Net observations report DATE: 20/01/28 02:34:56 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the LIGO/Virgo S200128d errorbox 37 sec after notice time and 322 sec after trigger time at 2020-01-28 02:25:33 UT, with upper limit up to 18.4 mag. The observations began at zenith distance = 41 deg. The sun altitude is -18.1 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) started inspect of the LIGO/Virgo S200128d errorbox 71 sec after notice time and 356 sec after trigger time at 2020-01-28 02:26:07 UT, with upper limit up to 18.1 mag. The observations began at zenith distance = 68 deg. The sun altitude is -71.2 deg. The galactic latitude b = 11 deg., longitude l = 332 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=11283 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 353 | 2020-01-28 02:25:33 | MASTER-SAAO | (15h 32m 49.48s , -42d 18m 49.4s) | C | 60 | 18.4 | 392 | 2020-01-28 02:26:07 | MASTER-IAC | (04h 23m 02.77s , +35d 36m 33.1s) | P| | 70 | 18.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26905 SUBJECT: LIGO/Virgo S200128d: Upper limits from IceCube neutrino searches DATE: 20/01/28 02:52:42 GMT FROM: Raamis Hussain at IceCube IceCube Collaboration (http://icecube.wisc.edu/) reports: Searches [1,2] for track-like muon neutrino events detected by IceCube consistent with the sky localization of gravitational-wave candidate S200128d in a time range of 1000 seconds [3] centered on the alert event time (2020-01-28 02:11:51.903 UTC to 2020-01-28 02:28:31.903 UTC) have been performed. During this time period IceCube was collecting good quality data. No significant track-like events are found in spatial coincidence of S200128d calculated from the map circulated in the 1-Preliminary notice. IceCube's sensitivity assuming an E^-2 spectrum (E^2 dN/dE) to neutrino point sources within the locations spanned by the 90% spatial containment of S200128d ranges from 0.029 to 0.966 GeV cm^-2 in a 1000 second time window. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu [1] Bartos et al. arXiv:1810.11467 (2018) and Countryman et al.arXiv:1901.05486 (2019) [2] PoS(ICRC2019)918 and Braun et al., Astroparticle Physics 29, 299 (2008) [3] Baret et al., Astroparticle Physics 35, 1 (2011) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26906 SUBJECT: LIGO/Virgo S200128d: Identification of a GW compact binary merger candidate DATE: 20/01/28 02:56:16 GMT FROM: Erik Katsavounidis at MIT The LIGO Scientific Collaboration and the Virgo Collaboration report: We identified the compact binary merger candidate S200128d during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2020-01-28 02:20:11.903 UTC (GPS time: 1264213229.903). The candidate was found by the PyCBC Live [1], CWB [2], MBTAOnline [3], and GstLAL [4] analysis pipelines. S200128d is an event of interest because its false alarm rate, as estimated by the online analysis, is 1.6e-08 Hz, or about one in 1 year, 11 months. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S200128d The classification of the GW signal, in order of descending probability, is BBH (97%), Terrestrial (3%), BNS (<1%), NSBH (<1%), or MassGap (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object has a mass < 3 solar masses (HasNS) is <1%. Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. Two sky maps are available at this time and can be retrieved from the GraceDB event page:  * bayestar.fits.gz,0, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 3 minutes after the candidate event time.  * bayestar.fits.gz,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 9 minutes after the candidate event time. The preferred sky map at this time is bayestar.fits.gz,1. For the bayestar.fits.gz,1 sky map, the 90% credible region is 2521 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 4031 +/- 1241 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo Public Alerts User Guide . [1] Nitz et al. PRD 98, 024050 (2018) [2] Klimenko et al. PRD 93, 042004 (2016) [3] Adams et al. CQG 33, 175012 (2016) [4] Messick et al. PRD 95, 042001 (2017) [5] Singer & Price PRD 93, 024013 (2016) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26907 SUBJECT: LIGO/Virgo S200128d: No counterpart candidates in HAWC observations DATE: 20/01/28 03:02:44 GMT FROM: Israel Martinez-Castellanos at UMD/HAWC The HAWC Collaboration (https://www.hawc-observatory.org) reports: The HAWC Collaboration performed a follow-up of the gravitational wave trigger S200128d. At the time of the trigger the HAWC local zenith was oriented towards (RA, Dec) = (64.3 deg, 18.9deg). 38% of the GW candidate sky location probability fell within our observable field of view (0-45 deg zenith angle). We performed a search for a short timescale emission using 6 sliding time windows (dt = 0.3s, 1s, 3s, 10s, 30s and 100s), shifted forward in time by 20% of their width. We searched the 95% probability containment area in a timescale-dependent time period, from t0-5dt to t0+10dt, where t0 is the time of the GW trigger. No significant gamma-ray detection above the background was observed. The sensitivity of this analysis is greatly dependent on zenith angle, ranging from 5deg to 45deg for the area searched in this analysis. The 5sigma detection sensitivity to a 1s (100s) burst in the 80-800GeV energy range goes from 1.2e-6 erg/cm^2 to 1.1e-4 erg/cm^2 (6.7e-6 erg/cm^2 to 5.0e-4 erg/cm^2), depending on the zenith angle. HAWC is a TeV gamma ray water Cherenkov array located in the state of Puebla, Mexico. It is sensitive to the energy range ~0.1-100TeV, and monitors 2/3 of the sky every day with an instantaneous field-of-view of ~2 sr. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26908 SUBJECT: LIGO/Virgo S200128d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation DATE: 20/01/28 03:20:37 GMT FROM: Francesca Onori at INAF/IAPS LIGO/Virgo S200128d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation Francesca Onori (IAPS, Italy), Alexis Coleiro V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) J. Rodi (IAPS-Roma, Italy) A. Coleiro (APC, France) S. Mereghetti (INAF IASF-Milano, Italy) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration Using INTEGRAL/SPI-ACS realtime data (following [1]) we have performed a search for a prompt gamma-ray counterpart of S200128d (GCN 26906). At the time of the event (2020-01-28 02:20:11 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 135 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (3.4% of optimal) response of ISGRI, somewhat suppressed (42% of optimal) response of IBIS/Veto, and somewhat suppressed (43 % of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was very stable (excess variance 1.1). We have performed a search for any impulsive events in INTEGRAL SPI- ACS (as described in [2]) data. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 2.6e-07 erg/cm^2 (within the 50% probability containment region of the source localization) for a burst lasting less than 1 s with a characteristic short GRB spectrum (an exponentially cut off power law with alpha=-0.5 and Ep=600 keV) occurring at any time in the interval within 300 s around T0. For a typical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the derived peak flux upper limit is ~2.3e-07 (5.4e-08) erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range. For the mean reported distance 4031.0 Mpc this corresponds to the limit on the total i sotropic equivalent energy in 1 s of 5e+50 erg for the short GRB spectrum and for a long GRB spectrum isotropic equivalent luminosity in 1 s (8 s) of 3.2e+50 erg/s (1e+50 erg/s) We report for completeness and in order of FAP, all excesses identified in the search region. We find: 1 possibly associated excess: T-T0 | scale | S/N | luminosity ( x 1e+51 erg/s) | FAP 4.73 | 0.5 | 4.1 | 16.5 +/- 5.64 +/- 14.1 | 0.0284 9 likely background excesses: T-T0 | scale | S/N | luminosity ( x 1e+51 erg/s) | FAP -201 | 5 | 4.3 | 5.28 +/- 1.77 +/- 4.5 | 0.0959 -128 | 1.5 | 5 | 11.3 +/- 3.25 +/- 9.64 | 0.128 6.65 | 0.75 | 3.1 | 9.85 +/- 4.59 +/- 8.38 | 0.175 -53.1 | 0.65 | 4 | 14.3 +/- 4.94 +/- 12.2 | 0.257 9.78 | 0.2 | 3.5 | 22.4 +/- 8.95 +/- 19 | 0.316 72.2 | 0.7 | 3.8 | 12.9 +/- 4.76 +/- 11 | 0.44 -9.6 | 0.15 | 3.4 | 2.48 +/- 1.03 +/- 2.11 | 0.566 271 | 3.3 | 3.5 | 5.06 +/- 2.18 +/- 4.31 | 0.577 45.6 | 1.15 | 3.1 | 8.14 +/- 3.7 +/- 6.93 | 0.646 Note that FAP estimates (especially at timescales above 2s) may be possibly further affected by enhanced non-stationary local background noise. This list excludes any excesses for which FAP is close to unity. All results quoted are preliminary. This circular is an official product of the INTEGRAL Multi-Messenger team. [1] Savchenko et al. 2017, A&A 603, A46 [2] Savchenko et al. 2012, A&A 541A, 122S -- Dr. Francesca Onori Postdoctoral Researcher IAPS, via Fosso del Cavaliere, 100, 00133 - Rome, Italy e-mail: francesca.onori@inaf.it Tel: +39 06 45488128 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26910 SUBJECT: LIGO/Virgo S200128d: Coverage and upper limits from MAXI/GSC observations DATE: 20/01/28 05:25:36 GMT FROM: Satoshi Sugita at Aoyama Gakuin U. S. Sugita, M. Serino (AGU), N. Kawai (Tokyo Tech), H. Negoro (Nihon U.), M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi, R. Takagi (Nihon U.), T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, H. Nishida, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech), S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, R. Shimomukai, M. Tominaga (JAXA), Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC) report on behalf of the MAXI team: We examined MAXI/GSC all-sky X-ray images (2-20 keV) after the LVC trigger S200128d at 2020-01-28 02:20:11.903 UTC (GCN 26906). At the trigger time of S200128d, the high-voltage of MAXI/GSC was on. The instantaneous field of view of GSC at the GW trigger time covered 1% of the 90% credible region of the bayestar sky map, in which we found no significant new X-ray source. The first one-orbit (92 min) scan observation with GSC after the event covered 92% of the 90% credible region of the bayestar skymap from 02:20:11 to 03:52:09 UTC (T0+0 to T0+5518 sec). No significant new source was found in the region in the one-orbit scan observation. A typical 1-sigma averaged upper limit obtained in one scan observation is 20 mCrab at 2-20 keV. If you require information about X-ray flux by MAXI/GSC at specific coordinates, please contact the submitter of this circular by email. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26912 SUBJECT: LIGO/Virgo S200128d : no neutrino counterpart candidate in ANTARES search DATE: 20/01/28 10:15:24 GMT FROM: Thierry Pradier at ANTARES/IPHC/U of Strasbourg M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite de Paris), M. Colomer (APC/Universite de Paris), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite de Paris), 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 S200128d event using the 90% contour of the Initial GW_SKYMAP probability map provided by the GW interferometers (GCN#26906 ). The ANTARES visibility at the time of the alert, together with the 50% and 90% contours of the probability map are shown at http://antares.in2p3.fr/GW/S200128d_Initial.png . Considering the location probability provided by the LIGO/Virgo collaborations, there is a 50.1% chance that the GW emitter was in the ANTARES **upgoing** field of view at the time of the alert. No up-going muon neutrino candidate events were recorded in the ANTARES sky during a +/-500s time-window centered on the time 2020-01-28 02:20:11 and in the 90% contour of the S200128d event. The expected number of atmospheric background events in the region visible by ANTARES is 6.46e-04 in the +/- 500s time window. An extended search during +/- 1 hour gives no up-going muon neutrino coincidence. The expected number of atmospheric background events in the region visible by ANTARES is 4.65e-03 in this larger time window. ANTARES is the largest undersea neutrino detector, installed in the Mediterranean Sea, and it is primarily sensitive to neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a competitive sensitivity to this position in the sky. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26916 SUBJECT: LIGO/Virgo S200128d: Upper limits from Fermi-GBM Observations DATE: 20/01/28 14:21:50 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood (NASA/MSFC) reports on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group For S200128d and using the bayestar.fits.gz,1 skymap, Fermi-GBM was observing 48.7% of the localization probability at event time. There was no Fermi-GBM onboard trigger around the event time of the LIGO/Virgo detection of GW trigger S200128d (GCN 26906). An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around merger time, and also identified no counterpart candidates. Part of the LVC localization region is behind the Earth for Fermi, located at RA=266.6, Dec=-24.9 with a radius of 67.5 degrees. We therefore set upper limits on impulsive gamma-ray emission for the LVC localization region visible to Fermi at merger time. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV, weighted by GW localization probability (in units of 10^-7 erg/s/cm^2): Timescale Soft Normal Hard ------------------------------------ 0.128 s: 2.5 3.2 8.3 1.024 s: 0.8 1.3 2.7 8.192 s: 0.2 0.4 1.0 Assuming the median luminosity distance of 4031 Mpc from the GW detection, we estimate the following intrinsic luminosity upper limits over the 1 keV-10 MeV energy range (in units of 10^50 erg/s): Timescale Soft Normal Hard ------------------------------------ 0.128s: 7.8 8.5 37. 1.024s: 2.4 3.4 12. 8.192s: 0.7 1.0 4.5 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26921 SUBJECT: LIGO/Virgo S200128d: no counterpart candidates in the Swift/BAT observations DATE: 20/01/28 21:21:12 GMT FROM: Amy Lien at GSFC S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), A. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB), A. A. Breeveld (MSSL-UCL), 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 (ASI-ASDC), S. Emery (UCL-MSSL), P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU), D. Hartmann (Clemson U.), J. A. Kennea (PSU), N. Klingler (PSU), H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J. A. Nousek (PSU), S. R. Oates (U. of Birmingham), P. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), M. Perri (ASDC), J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (U. Toronto), 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 S200128d (LIGO/VIRGO Collaboration GCN Circ. 26906), where T0 is the LVC trigger time (2020-01-28T02:20:11.903 UTC). The center of the BAT field of view (FOV) at T0 is RA = 40.666 deg, DEC = 0.035 deg, and the roll angle is 242.886 deg. The BAT FOV (>10% partial coding) covers 24.07% of the integrated LVC localization probability, and 23.84% of the galaxy convolved probability (Evans et al. 2016). Note that the sensitivity in the BAT FOV changes with the partial coding fraction. Please see the BAT FOV figure in the summary page (link below) for the specific location of the LVC region relative to the BAT FOV. 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. 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 ~ 1.01 x 10^-7 erg/s/cm^2. Assuming a luminosity of ~ 2 x 10^47 erg/s (similar to GW170817) and an average Epeak of ~ 400 keV for short GRBs (Bhat et al. 2016), this flux upper limit corresponds to a distance of ~ 71.59 Mpc. Event data are available from T0-45.29 s to T0+44.84 s. No significant detections (above our typical image threshold of ~ 6.5 to 7 sigma) are found in the 15-350 keV images created using intervals of T0-0.1 to T0+0.1 s, T0-2 s to T0+8 s, and the whole event data range. BAT retains decreased, but significant, sensitivity to rate increases for gamma-ray events outside of its FOV. About 25.22% 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 higher than those within the FOV. The results of the BAT analysis are available at https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S200128d/web/source_public.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26923 SUBJECT: LIGO/Virgo S200128d: No counterpart candidates in KAIT observations DATE: 20/01/29 05:01:15 GMT FROM: Weikang Zheng at UC Berkeley Shaunak Modak, Andrew Hoffman, Nachiket Girish, Yukei Murakami, WeiKang Zheng, and Alexei V. Filippenko (UC Berkeley) report on behalf of the Lick/KAIT GW follow-up team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, observed the 90% region of the gravitational-wave event S200128d (GCN 26906) detected by LIGO/Virgo. More than one thousand galaxies were selected from the Glade catalog V1.0 (Dalya et al., 2018, MNRAS, 479, 2374; http://aquarius.elte.hu/glade/) according to their priority score. KAIT observed 100 of them based on their priority scores and elevation visibility, with each clear-filter exposure time being 60 s. The first image was taken at 02:32:19, Jan. 28th UT, about 12.0 minutes after the trigger, and the last image at 10:19:35 UT. Our typical limiting mag is 19.0. No viable counterparts were identified and the analysis is ongoing. A full list of galaxies observed by KAIT is given below. GladeID UT(Jan28) RA_J2000 Dec_J2000 ----------------------------------------------- G0696216 02:32:19 01:17:45.1378 -25:50:21.1524 G0795121 02:33:30 01:37:49.0049 -23:38:01.3056 G0882384 02:34:39 01:44:47.0527 -23:23:18.2724 G1619053 02:35:52 01:45:50.352 -09:18:49.428 G0665450 02:37:06 01:47:45.3487 -21:50:00.51 G0824841 02:38:15 01:48:39.0418 -18:43:43.212 G0784259 02:39:27 01:49:47.124 -21:54:26.9496 G0710198 02:40:37 01:52:03.413 -20:09:58.4748 G0571685 02:41:46 01:56:32.7274 -20:02:54.114 G0747645 02:42:58 01:57:01.9176 -17:01:23.4948 G0648368 02:44:07 01:59:04.5048 -19:30:01.4292 G0565331 02:45:16 02:01:06.5748 -18:53:47.8644 G0814247 02:46:25 02:01:28.493 -18:04:01.8768 G0817926 02:47:35 02:01:46.837 -16:24:20.934 G1614837 02:48:46 02:03:34.632 -09:25:40.188 G0816503 02:49:57 02:04:09.7622 -15:58:48.4284 G0786849 02:51:07 02:04:59.6902 -16:08:05.1684 G0750785 02:52:16 02:05:29.7775 -18:02:35.2572 G0656369 02:53:25 02:10:30.553 -13:29:37.0176 G0081229 02:54:35 02:11:53.1912 -12:06:25.776 G0731349 02:55:46 02:25:23.2416 -07:50:24.2664 G0594730 02:56:55 02:26:58.9747 -04:35:26.9484 G0633562 02:58:05 02:27:09.342 -02:52:19.956 G0001576 02:59:14 02:30:42.8393 -02:56:20.4144 G0653886 03:00:23 02:36:56.6858 -02:11:59.1648 G1139246 03:01:35 02:47:12.2479 +05:39:53.6004 G0756115 03:02:46 02:57:53.0868 +13:01:50.8656 G0641223 03:03:55 02:58:57.8184 +13:34:58.332 G0576258 03:05:14 03:41:17.3546 +26:40:14.7324 G0582436 03:06:25 03:54:09.8887 +34:07:08.4396 G0731349 03:50:59 02:25:23.2416 -07:50:24.2664 G0594730 03:52:09 02:26:58.9747 -04:35:26.9484 G0001576 03:54:27 02:30:42.8393 -02:56:20.4144 G0653886 03:55:37 02:36:56.6858 -02:11:59.1648 G1139246 03:56:48 02:47:12.2479 +05:39:53.6004 G0756115 03:57:59 02:57:53.0868 +13:01:50.8656 G0641223 03:59:09 02:58:57.8184 +13:34:58.332 G0576258 04:00:25 03:41:17.3546 +26:40:14.7324 G0582436 04:01:37 03:54:09.8887 +34:07:08.4396 G0770459 04:52:59 04:09:18.3919 +33:53:23.9172 G0796246 04:54:16 04:11:56.4852 +39:30:13.32 G0565674 04:55:26 04:17:34.9824 +36:08:05.1144 G1167642 04:56:35 04:21:29.436 +36:56:57.2568 G0650034 04:57:44 04:22:59.9047 +43:06:38.844 G0609806 04:58:56 04:28:28.9546 +38:21:29.9592 G0487836 05:00:05 04:30:09.049 +42:44:48.8076 G0649095 05:01:14 04:38:28.3392 +44:02:13.6752 G0736266 05:02:26 04:38:58.2751 +39:16:50.6856 G0567652 05:03:35 04:41:00.9706 +37:10:40.3248 G0734583 05:04:44 04:43:34.3745 +38:12:34.4592 G0791297 05:05:56 04:49:09.0638 +45:00:39.3984 G0726428 05:07:05 04:49:37.8058 +43:47:43.5876 G0651979 05:08:15 04:50:06.6852 +45:03:05.7384 G1509641 05:09:47 05:42:36.336 +49:51:07.38 G0225879 05:11:12 05:53:42.9274 +53:37:11.3232 G0630005 05:12:25 06:02:29.2512 +50:43:10.2864 G0599403 05:13:53 06:59:38.13 +54:11:47.3424 G1418861 05:15:02 07:04:52.1942 +55:35:28.3812 G0646693 05:16:13 07:20:26.6839 +56:23:27.1968 G0476768 05:17:32 08:00:08.5181 +56:21:56.232 G0671466 05:18:41 08:01:45.9026 +56:33:12.0564 G0615908 05:19:57 08:58:36.4855 +54:19:02.676 G0701014 05:21:06 09:01:30.0953 +55:39:16.6356 G0706321 05:22:17 09:35:58.8941 +54:36:39.0384 G0761971 05:23:29 09:46:53.3424 +54:26:45.2544 G0575796 07:34:10 10:32:38.4924 +53:09:24.0516 G0631724 07:35:17 10:33:47.8418 +52:22:16.4748 G0776673 07:36:35 10:37:12.2278 +50:07:14.3184 G0784581 07:37:48 10:38:51.8261 +53:58:18.9264 G0273464 07:38:59 10:48:09.3127 +48:19:53.2668 G0600260 07:40:09 10:51:31.6625 +49:30:08.6652 G0899439 07:41:19 11:04:22.3205 +48:38:11.3352 G0576057 07:42:28 11:06:10.4479 +48:16:03.6804 G0234381 07:43:39 11:21:35.8886 +48:02:52.2924 G0726921 07:44:49 11:24:06.4819 +48:41:46.518 G0609396 07:45:58 11:24:27.323 +48:52:45.8076 G0827094 07:47:10 11:43:39.5911 +46:21:20.2932 G0732456 07:48:21 12:04:57.9053 +43:08:59.0316 G0639300 07:49:31 12:06:13.4436 +45:20:01.176 G0769163 07:50:40 12:12:16.9848 +45:30:49.7556 G1437067 07:51:49 12:15:59.4799 +41:22:29.478 G1836334 07:52:58 12:16:07.92 +40:36:49.32 G0668285 07:54:08 12:16:46.5235 +44:40:15.8124 G0810953 07:55:17 12:21:13.147 +41:52:13.9476 G1699892 07:56:26 12:26:42.24 +43:47:04.056 G0787284 07:57:36 12:27:55.0891 +45:26:58.452 G1817097 07:58:45 12:28:48.72 +44:52:08.58 G0783585 07:59:55 12:30:34.9877 +42:11:29.9544 G0613621 08:01:04 12:31:54.6314 +40:34:25.2084 G0356212 08:02:14 12:34:18.4534 +40:49:34.7808 G0881944 08:03:23 12:35:09.3823 +39:27:05.634 G0571256 08:04:33 12:38:43.5792 +41:33:07.7148 G0761416 08:05:42 12:42:10.2612 +42:02:21.1884 G0782000 10:10:14 13:06:56.737 +18:53:53.6892 G1143431 10:12:33 13:07:18.8268 +17:41:53.7972 G0750196 10:13:42 13:07:34.0577 +16:21:22.8204 G1143718 10:14:52 13:08:22.0642 +15:42:20.9808 G1435594 10:16:03 13:08:45.3038 +18:46:13.1016 G0743613 10:18:26 13:11:03.534 +19:01:12.8244 G0595223 10:19:35 13:12:38.1151 +15:38:21.0408 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26924 SUBJECT: LIGO/Virgo S200128d: Upper limits from CALET observations DATE: 20/01/29 06:06:04 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET N. Cannady (GSFC/UMBC), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger time of S200128d T0 = 2020-01-28 02:20:11.903 UT (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ.26906). No CGBM on-board trigger occurred around the event time. Based on the LIGO-Virgo localization sky map, the summed LIGO probabilities inside the CGBM HXM (7 - 3000 keV) and SGM (40 keV - 28 MeV) fields of view are 26 % and 49 %, respectively (and 65 % credible region of the initial sky map was above the horizon). The HXM and SGM fields of view were centered at RA = 134.1 deg, Dec = +30.5 deg and RA = 126.1 deg, Dec = +23.4 deg at T0, respectively. Based on the analysis of the light curve data with 0.125 sec time resolution from T0-60 sec to T0+60 sec, we found no significant excess around the trigger time in either the HXM or the SGM data. The CALET Calorimeter (CAL) was operating in the high energy trigger mode at the trigger time of S200128d. Using the 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 in the overwrap region with the LIGO-Virgo high probability localization region. The 90% upper limit of CAL is 4.6 x 10^-6 erg/cm^2/s (10-100 GeV) when the summed LIGO-Virgo probability reaches 10%. The CAL FOV was centered at RA = 126.1 deg, DEC = +23.4 deg at T0. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26925 SUBJECT: LIGO/Virgo S200128d: No counterpart candidates in Fermi-LAT observations DATE: 20/01/29 06:16:52 GMT FROM: Magnus Axelsson at Stockholm U. M. Axelsson (KTH & Stockholm Univ.), F. Longo (University and INFN, Trieste), M. Kovacevic (INFN Perugia), E. Bissaldi (Politecnico & INFN Bari), D. Kocevski (NASA/MSFC), N. Omodei (Stanford Univ.) and M. Arimoto (Kanazawa University) report on behalf of the Fermi-LAT Collaboration: We have searched data collected by the Fermi Large Area Telescope (LAT) on January 28, 2020, for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger S200128d (GCN 26906). We define "instantaneous coverage" as the integral over the region of the LIGO 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. Fermi-LAT had an instantaneous coverage of ~35% of the LIGO probability at the time of the trigger (T0 = 2020-01-28 02:20:11.903 UTC), and reached 100% cumulative coverage after ~4.2 ks. We performed a search for a transient counterpart within the observed region of the 90% contour of LIGO map in a fixed time window from T0 to T0 + 10 ks. 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, and no additional excesses were found. Energy flux upper bounds for the fixed time interval between 100 MeV and 1 GeV for this search vary between 1.4e-10 and 3.0e-09 [erg/cm^2/s]. The Fermi-LAT point of contact for this event is Makoto Arimoto (arimoto@se.kanazawa-u.ac.jp) 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: 26934 SUBJECT: LIGO/Virgo S200128d: upper limits from AGILE/GRID observations DATE: 20/01/29 14:22:55 GMT FROM: Francesco Verrecchia at SSDC,INAF-OAR F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano (INAF/IAPS), F. Lucarelli, A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN Trieste), report on behalf of the AGILE Team: In response to the LIGO-Virgo GW event S200128d at T0 = 2020-01-28 02:20:11.903 UTC a preliminary analysis of the AGILE data shows that no AGILE/MCAL and AGILE/GRID data were available at T0 due to a telemetry gap. We performed an analysis of the GRID data in the energy range 50 MeV - 10 GeV over time intervals before and after T0, where good exposure of the S200128d 90% c.l. LR was available. No candidate gamma-ray transient was detected. The following preliminary GRID value of 3-sigma upper limit (UL) is obtained: from 3.6e-08 to 3.4e-06 erg cm^-2 s^-1, with exposure of about 44% of the LR over the time interval ( T0 + 200 s ; T0 + 300 s ); 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: 26947 SUBJECT: LIGO/Virgo S200128d : No significant candidates in FRAM - TAROT - GRANDMA observations DATE: 20/01/31 09:00:44 GMT FROM: Cosmin Stachie at Artemis, Nice, France C. Stachie (Artemis), S. Beradze (Iliauni), D. A. Kann (HETH/IAA-CSIC), Z. Vidadi (SHAO), S. Karpov (FZU), M. Masek (FZU), M. Prouza (FZU), M. Boer (Artemis), N. Christensen (Artemis), L. Eymar (Artemis), A. Klotz (IRAP), K. Noysena (Artemis, IRAP), S. Antier (APC), A. Coleiro (APC), D. Corre (IJCLab), M. Coughlin (UMN), D. Coward (OzGrav-UWA), J.G. Ducoin (IJCLab), B. Gendre (OzGrav-UWA), P. Hello (IJCLab), N. Kochiashvili (Iliauni), C. Lachaud (APC), N. Leroy (IJCLab), C. Thoene (HETH/IAA-CSIC), D. Turpin (AIM-CEA), X. Wang (THU) report on behalf of the FRAM, TAROT and GRANDMA collaborations. We performed tiled observations of LIGO/Virgo S200128d event with the FRAM-Auger, FRAM-CTA-N, TAROT-Calern (TCA), TAROT-Chili (TCH) telescopes. FRAM-Auger is located at Pierre Auger Observatory. FRAM-CTA-N is located at Observatorio del Roque de los Muchachos. TCA is located at Calern site at the Cote d'Azur observatory. TCH is located at La Silla ESO observatory (LaS/ESO). The following table shows for each telescope: the delay in minutes from the trigger, which filter is used, the field of view of the telescope in degrees and the typical limiting magnitude (AB mag) for a given exposure in seconds (s). +-------------+---------+----------+-------------+------------+ | Telescope | Delay | Filter | f.o.v. | Limiting | | | [min] | | [deg] | Mag. | |-------------+---------+----------+-------------+------------| | FRAM-Auger | 27 | R | 1.0 x 1.0 | 18.0 (60s) | | FRAM-CTA-N | 24 | R | 0.45 x 0.45 | 17.0 (90s) | | TCA | 1148 | Clear | 1.9 x 1.9 | 18.0 (60s) | | TCH | 155 | Clear | 1.9 x 1.9 | 18.0 (60s) | +-------------+---------+----------+-------------+------------+ We performed the following joint tiled observations [1] : +-------------+------------+------------+---------+---------+---------+ | Telescope | TStart | TEnd | RA | DEC | Proba | | | [UTC] | [UTC] | [deg] | [deg] | [%] | |-------------+------------+------------+---------+---------+---------| | FRAM-Auger | 2020-01-28 | 2020-01-28 | 60.583 | 33.568 | 0.1 | | | 02:46:24 | 02:50:51 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 59.240 | 31.622 | 0.1 | | | 02:51:26 | 02:55:53 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 233.660 | -44.270 | 0.1 | | | 04:14:01 | 04:18:28 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 230.504 | -41.351 | 0.1 | | | 04:19:04 | 04:23:31 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 226.623 | -34.541 | 0.1 | | | 05:17:46 | 05:22:12 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 228.980 | -37.459 | 0.1 | | | 05:22:47 | 05:27:14 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 229.655 | -38.432 | 0.1 | | | 05:27:48 | 05:32:15 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 227.755 | -37.459 | 0.1 | | | 05:32:50 | 05:37:17 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 230.350 | -39.405 | 0.1 | | | 05:37:53 | 05:42:20 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 231.064 | -40.378 | 0.1 | | | 05:42:54 | 05:47:21 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 236.250 | -46.216 | 0.1 | | | 06:31:19 | 06:35:46 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 227.803 | -34.541 | 0.1 | | | 06:36:24 | 06:40:51 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 234.483 | -45.243 | 0.1 | | | 06:41:27 | 06:45:54 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 237.143 | -47.189 | 0.1 | | | 06:46:29 | 06:50:56 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 230.204 | -37.459 | 0.1 | | | 06:51:33 | 08:00:09 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 224.430 | -31.622 | 0.1 | | | 08:00:46 | 08:05:13 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 228.414 | -38.432 | 0.1 | | | 08:05:48 | 08:10:15 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 233.333 | -43.297 | 0.1 | | | 08:10:52 | 08:15:18 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 235.862 | -45.243 | 0.1 | | | 08:15:54 | 08:20:21 | | | | | FRAM-Auger | 2020-01-28 | 2020-01-28 | 234.667 | -43.297 | 0.1 | | | 08:20:55 | 08:25:22 | | | | | ----- | ----- | ----- | ----- | ----- | ----- | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 71.752 | 42.604 | <0.1 | | | 02:44:06 | 03:07:01 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 65.302 | 38.672 | <0.1 | | | 02:48:28 | 03:11:23 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 67.761 | 40.419 | <0.1 | | | 02:52:54 | 03:15:44 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 63.885 | 37.136 | <0.1 | | | 03:16:00 | 03:20:06 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 66.531 | 38.672 | <0.1 | | | 03:20:26 | 03:24:32 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 65.125 | 37.897 | <0.1 | | | 03:24:45 | 03:28:51 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 64.770 | 37.361 | <0.1 | | | 03:29:10 | 03:33:16 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 67.760 | 38.672 | <0.1 | | | 03:33:33 | 03:37:39 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 65.980 | 39.645 | <0.1 | | | 03:37:54 | 03:42:00 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 228.239 | -37.348 | <0.1 | | | 07:00:51 | 07:04:57 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 228.425 | -36.812 | <0.1 | | | 07:05:11 | 07:09:16 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 229.117 | -37.348 | <0.1 | | | 07:09:29 | 07:13:35 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 230.179 | -38.334 | <0.1 | | | 07:13:49 | 07:17:55 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 227.368 | -35.163 | <0.1 | | | 07:18:28 | 07:22:34 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 227.361 | -37.348 | <0.1 | | | 07:22:48 | 07:26:54 | | | | | FRAM-CTA-N | 2020-01-28 | 2020-01-28 | 230.005 | -37.348 | <0.1 | | | 07:27:08 | 07:29:08 | | | | | ----- | ----- | ----- | ----- | ----- | ----- | | TCA | 2020-01-28 | 2020-01-29 | 61.323 | 34.805 | 0.4 | | | 21:27:35 | 00:33:56 | | | | | TCA | 2020-01-28 | 2020-01-29 | 66.832 | 38.991 | 0.3 | | | 21:34:18 | 00:40:37 | | | | | TCA | 2020-01-28 | 2020-01-28 | 70.467 | 42.703 | 0.3 | | | 21:46:45 | 22:53:03 | | | | | TCA | 2020-01-28 | 2020-01-28 | 63.559 | 35.280 | 0.3 | | | 21:53:29 | 22:59:48 | | | | | TCA | 2020-01-28 | 2020-01-28 | 57.317 | 29.713 | 0.3 | | | 22:00:14 | 23:06:33 | | | | | TCA | 2020-01-28 | 2020-01-28 | 65.154 | 37.136 | 0.3 | | | 23:21:05 | 23:23:05 | | | | | ----- | ----- | ----- | ----- | ----- | ----- | | TCH | 2020-01-28 | 2020-01-30 | 236.439 | -47.232 | 0.4 | | | 04:55:03 | 09:27:07 | | | | | TCH | 2020-01-28 | 2020-01-30 | 232.208 | -39.959 | 0.4 | | | 05:16:40 | 07:23:02 | | | | | TCH | 2020-01-28 | 2020-01-30 | 227.365 | -36.323 | 0.4 | | | 05:23:26 | 07:29:47 | | | | | TCH | 2020-01-28 | 2020-01-30 | 232.731 | -41.777 | 0.4 | | | 05:30:10 | 07:36:31 | | | | | TCH | 2020-01-28 | 2020-01-30 | 223.609 | -29.050 | 0.4 | | | 05:42:41 | 07:48:57 | | | | | TCH | 2020-01-28 | 2020-01-30 | 237.200 | -49.050 | 0.4 | | | 05:51:36 | 07:55:42 | | | | | TCH | 2020-01-28 | 2020-01-30 | 224.144 | -30.868 | 0.4 | | | 05:56:12 | 08:02:14 | | | | | TCH | 2020-01-28 | 2020-01-28 | 241.967 | -52.686 | 0.3 | | | 06:12:54 | 08:42:48 | | | | | TCH | 2020-01-28 | 2020-01-30 | 240.950 | -50.868 | 0.3 | | | 06:19:40 | 08:21:39 | | | | | TCH | 2020-01-28 | 2020-01-30 | 246.260 | -54.505 | 0.3 | | | 06:24:14 | 08:28:21 | | | | | TCH | 2020-01-28 | 2020-01-30 | 230.265 | -41.777 | 0.3 | | | 06:34:31 | 08:41:03 | | | | | TCH | 2020-01-28 | 2020-01-30 | 231.654 | -43.595 | 0.3 | | | 06:41:17 | 08:47:37 | | | | | TCH | 2020-01-28 | 2020-01-30 | 225.394 | -34.505 | 0.3 | | | 06:48:00 | 08:54:21 | | | | | TCH | 2020-01-28 | 2020-01-28 | 229.824 | -39.959 | 0.4 | | | 07:27:31 | 07:33:50 | | | | | TCH | 2020-01-28 | 2020-01-30 | 240.012 | -49.050 | 0.4 | | | 07:34:15 | 07:10:36 | | | | | TCH | 2020-01-29 | 2020-01-29 | 227.617 | -34.505 | 0.3 | | | 05:00:12 | 05:02:12 | | | | | TCH | 2020-01-29 | 2020-01-30 | 249.525 | -56.323 | 0.3 | | | 05:23:56 | 06:30:48 | | | | | TCH | 2020-01-30 | 2020-01-30 | 234.189 | -43.595 | 0.4 | | | 05:06:42 | 05:13:01 | | | | | TCH | 2020-01-30 | 2020-01-30 | 235.733 | -45.414 | 0.4 | | | 05:36:58 | 08:08:55 | | | | +-------------+------------+------------+---------+---------+---------+ TStart and TEnd refers respectively to the time of the first and last exposure for a given tile. Observations are not necessarily continuous in this interval. The Probability refers to the 2D spatial probability of the GW skymap enclosed in a given tile. These observations cover about 9.7% of the cumulative probability of the BAYESTAR skymap created on 2020-01-28 02:22:21 (UTC). The coverage map is available at: https://grandma-owncloud.lal.in2p3.fr/index.php/s/XgtMhPRxcyL09gR/download?path=%2F&files=GRANDMA_S200128d_1580458038.svg No significant transient candidates were found during our low latency analysis [2,3]. GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of robotic telescopes connected all over the world with both photometry and spectrometry capabilities for Time- domain Astronomy [2](https://grandma.lal.in2p3.fr/). Details on the different telescopes are available on the GRANDMA web pages. [1] M. W Coughlin et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz2485 [2] S. Antier et al., MNRAS 2019, https://doi.org/10.1093/mnras/stz3142 [3] K. Noysena et al., ApJ 2019, arXiv:1910.02770 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26948 SUBJECT: LIGO/Virgo S200128d: no counterpart candidate in SVOM/GWAC observations DATE: 20/01/31 09:44:55 GMT FROM: Xuhui Han at NAOC/SVOM L. P. Xin (NAOC), D. Turpin (CEA/AIM), X. H. Han (NAOC), P. Maggi (CNRS/ObAS), G. W. Li (NAOC) report on behalf of the SVOM Multi Messenger Astronomy and GWAC teams (http://www.svom.fr/en/svom-mma-and-gwac-team): We observed 24 (~3600 square deg) sky regions to cover the skymap of the advanced LIGO/Virgo trigger S200128d (GCN # 26906), with SVOM/GWAC, at Xinglong Observatory. SVOM/GWAC is equipped with two sets of wide angle cameras: - FFOV cameras (FOV~900 square degrees/camera, aperture = 3.5 cm), - JFOV cameras (FOV~150 square degrees/camera, aperture = 18 cm). SVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras, working in the unfiltered band. The observations are operated in time-series mode, taking one exposure every 25 seconds (20s exposure + 5s readout). The observed and processed regions enclosed an estimated 41.5% of the probability of the advanced LIGO/Virgo skymap. Images were taken between ~ 1 day 8 hours and ~ 1 day 19 hours after the GW trigger time. The coordinates of the 24 sky regions observed and their observation times and covered probability are listed below: Id Ra Dec start (UTC) end (UTC) Proba. Cam. 1 07:26:22.5 52:57:12 2020-01-29 10:55:07 2020-01-29 11:22:13 0.026 JFOV 2 05:56:38.9 65:08:37 2020-01-29 11:06:26 2020-01-29 11:18:58 0.004 JFOV 3 06:12:15.3 53:15:18 2020-01-29 11:09:16 2020-01-29 11:22:12 0.057 JFOV 4 07:44:20.8 51:50:32 2020-01-29 11:25:03 2020-01-29 11:51:47 0.017 JFOV 5 09:06:04.5 52:07:04 2020-01-29 11:31:07 2020-01-29 11:45:42 0.010 JFOV 6 11:13:44.4 53:09:28 2020-01-29 13:20:41 2020-01-29 13:48:54 0.006 JFOV 7 09:59:12.0 53:29:36 2020-01-29 13:20:41 2020-01-29 13:48:53 0.011 JFOV 8 11:02:15.3 52:27:35 2020-01-29 13:59:08 2020-01-29 14:29:24 0.007 JFOV 9 13:30:27.8 02:35:47 2020-01-29 18:03:07 2020-01-29 18:31:15 0.012 JFOV 10 14:14:55.2 02:19:21 2020-01-29 18:03:07 2020-01-29 18:31:16 0.016 JFOV 11 13:29:46.0 14:38:49 2020-01-29 18:10:38 2020-01-29 18:31:15 0.007 JFOV 12 14:43:27.3 -14:26:44 2020-01-29 19:41:57 2020-01-29 21:15:50 0.039 JFOV 13 14:42:23.5 -2:16:58 2020-01-29 19:51:29 2020-01-29 21:15:59 0.006 JFOV 14 01:16:21.5 -15:28:16 2020-01-29 11:55:59 2020-01-29 12:18:06 0.003 JFOV 15 02:08:49.9 -15:25:18 2020-01-29 11:55:59 2020-01-29 12:18:55 0.006 JFOV 16 02:42:44.0 02:33:55 2020-01-29 10:29:21 2020-01-29 10:50:23 0.032 JFOV 17 02:41:52.7 14:37:03 2020-01-29 10:29:46 2020-01-29 10:50:23 0.033 JFOV 18 03:27:08.5 02:20:08 2020-01-29 10:37:52 2020-01-29 10:50:24 0.004 JFOV 19 03:28:18.0 18:21:27 2020-01-29 10:51:19 2020-01-29 11:19:23 0.058 JFOV 20 02:36:11.9 18:14:12 2020-01-29 10:52:39 2020-01-29 11:19:23 0.015 JFOV 21 04:10:49.1 36:06:55 2020-01-29 11:56:45 2020-01-29 12:10:03 0.082 JFOV 22 04:02:39.9 31:31:29 2020-01-29 11:38:13 2020-01-29 11:50:46 0.079 JFOV 23 04:26:07.4 35:11:34 2020-01-29 10:20:42 2020-01-29 10:49:06 0.073 JFOV 24 05:27:37.7 35:23:43 2020-01-29 10:23:32 2020-01-29 10:42:37 0.004 JFOV The sky coverage map is available at: http://cmm.svom.cn/gwpub/O3/S200128d/S200128d.png (user:svomo3 pwd:gwo3). Weather conditions were clear during the observations. An average 3-sigma limiting magnitude of 16 mag in the R band was obtained in the single frames. No credible new source was detected by our online pipeline during follow-up observations. A more detailed image analysis including co-addition is ongoing with our offline pipeline to search for transient candidates. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26978 SUBJECT: LIGO/Virgo S200128d: Upper limits from Konus-Wind observations DATE: 20/02/03 19:34:06 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, 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 S200128d (2020-01-28 02:20:11.903 UTC, hereafter T0; LIGO/Virgo Collaboration GCN Circ. 26906). No triggered KW GRBs happened between ~2 days before and ~2 days after T0. The closest waiting-mode GRB was observed ~2.5 hours before 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 20 - 1500 keV fluence to 8.0x10^-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 2.4x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s scale). All the quoted values are preliminary