//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25604 SUBJECT: LIGO/Virgo S190901ap: Upper limits from IceCube neutrino searches DATE: 19/09/02 00:13:09 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 S190901ap in a time range of 1000 seconds [3] centered on the alert event time (2019-09-01 23:22:41.838 UTC to 2019-09-01 23:39:21.838 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 S190901ap 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 S190901ap ranges from 0.029 to 1.150 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] Braun et al., Astroparticle Physics 29, 299 (2008) [3] Baret et al., Astroparticle Physics 35, 1 (2011) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25605 SUBJECT: LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation DATE: 19/09/02 00:18:14 GMT FROM: Enrico Bozzo at ISDC E. Bozzo (ISDC/UniGE, Switzerland), S. Schanne (CEA, France) 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 S190901ap. At the time of the event (2019-09-01 23:31:01 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 61 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (21% of optimal) response of ISGRI, somewhat suppressed (46% of optimal) response of IBIS/Veto, and near-optimal (87% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was rather stable (excess variance 1.2). 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 1.7e-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 ~1.5e-07 (5.8e-08) erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range. For the mean reported distance 242.0 Mpc this corresponds to the limit on the total isotropic equivalent energy in 1 s of 1.2e+48 erg for the short GRB spectrum and for a long GRB spectrum isotropic equivalent luminosity in 1 s (8 s) of 1e+48 erg/s (4.1e+47 erg/s) We report for completeness and in order of FAP, all excesses identified in the search region. We find: 1 possibly associated excess: scale | T | S/N | luminosity ( x 1e+48 erg/s) | FAP 2.25 | 17.2 | 3.7 | 22.4 +/- 7.96 +/- 18.8 | 0.0343 4 likely background excesses: scale | T | S/N | luminosity ( x 1e+48 erg/s) | FAP 0.1 | -6.37 | 3.5 | 9.72 +/- 3.82 +/- 8.16 | 0.469 0.55 | 171 | 4.8 | 5.74 +/- 1.62 +/- 4.82 | 0.544 0.1 | -23.9 | 4 | 11.1 +/- 3.83 +/- 9.29 | 0.808 0.1 | -28.8 | 4.1 | 11.4 +/- 3.84 +/- 9.58 | 0.831 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 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25606 SUBJECT: LIGO/Virgo S190901ap: Identification of a GW compact binary merger candidate DATE: 19/09/02 00:18:29 GMT FROM: Shasvath J. Kapadia at U. of Wisconsin, Milwaukee The LIGO Scientific Collaboration and the Virgo Collaboration report: We identified the compact binary merger candidate S190901ap during real-time processing of data from LIGO Livingston Observatory (L1) and Virgo Observatory (V1) at 2019-09-01 23:31:01.838 UTC (GPS time: 1251415879.838). The candidate was found by the GstLAL [1] analysis pipeline. S190901ap is an event of interest because its false alarm rate, as estimated by the online analysis, is 7e-09 Hz, or about one in 4 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S190901ap The classification of the GW signal, in order of descending probability, is BNS (86%), Terrestrial (14%), BBH (<1%), MassGap (<1%), or NSBH (<1%). Assuming the candidate is astrophysical in origin, there is strong evidence for the lighter compact object having a mass < 3 solar masses (HasNS: >99%). Using the masses and spins inferred from the signal, there is strong evidence for matter outside the final compact object (HasRemnant: >99%). One sky map is available at this time and can be retrieved from the GraceDB event page: * bayestar.fits.gz, an updated localization generated by BAYESTAR [2], distributed via GCN notice about 5 minutes after the candidate For the bayestar.fits.gz sky map, the 90% credible region is 13613 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 242 +/- 81 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] Messick et al. PRD 95, 042001 (2017) [2] Singer & Price PRD 93, 024013 (2016) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25607 SUBJECT: LIGO/Virgo S190901ap: No counterpart candidates in HAWC observations DATE: 19/09/02 02:11:08 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 S190901ap (GCN #25606). At the time of the trigger the HAWC local zenith was oriented towards (RA, Dec) = (236.1 deg, 19.1 deg). 31% 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 0 deg to 45 deg 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 (6.4e-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: 25609 SUBJECT: LIGO/Virgo S190901ap Global MASTER-Net observations report DATE: 19/09/02 03:58:08 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 (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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the LIGO/Virgo S190901ap errorbox 7875 sec after trigger time at 2019-09-02 01:42:16 UT, with upper limit up to 19.2 mag. The observations began at zenit distance = 69 deg. The sun altitude is -43.8 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=10759 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 7966 | 2019-09-02 01:42:16 | MASTER-OAFA | (01h 33m 01.151s , -36d 05m 50.60s) | C | 180 | 17.5 | 8220 | 2019-09-02 01:46:30 | MASTER-OAFA | (01h 30m 42.740s , -34d 05m 28.87s) | C | 180 | 19.3 | 9275 | 2019-09-02 02:04:06 | MASTER-OAFA | (01h 42m 53.530s , -36d 05m 18.14s) | C | 180 | 16.4 | 9723 | 2019-09-02 02:11:33 | MASTER-OAFA | (01h 40m 22.971s , -34d 05m 40.56s) | C | 180 | 16.4 | 11293 | 2019-09-02 02:37:44 | MASTER-OAFA | (02h 34m 46.030s , -32d 04m 54.73s) | C | 180 | 18.4 | 11968 | 2019-09-02 02:48:58 | MASTER-OAFA | (02h 53m 39.194s , -32d 04m 16.95s) | C | 180 | 18.6 | 12192 | 2019-09-02 02:52:43 | MASTER-OAFA | (02h 46m 42.695s , -28d 04m 41.93s) | C | 180 | 18.5 | 12419 | 2019-09-02 02:56:29 | MASTER-OAFA | (02h 55m 48.250s , -28d 04m 13.09s) | C | 180 | 18.4 | 12644 | 2019-09-02 03:00:15 | MASTER-OAFA | (02h 59m 15.321s , -30d 04m 29.16s) | C | 180 | 18.4 | 12874 | 2019-09-02 03:04:05 | MASTER-OAFA | (02h 52m 39.948s , -26d 04m 15.46s) | C | 180 | 18.6 | 13324 | 2019-09-02 03:11:35 | MASTER-OAFA | (03h 04m 50.900s , -28d 04m 21.90s) | C | 180 | 18.5 | 13778 | 2019-09-02 03:19:09 | MASTER-OAFA | (03h 08m 31.010s , -30d 03m 57.77s) | C | 180 | 18.5 | 14227 | 2019-09-02 03:26:37 | MASTER-OAFA | (03h 01m 32.460s , -26d 04m 24.25s) | C | 180 | 18.9 | 15137 | 2019-09-02 03:41:48 | MASTER-OAFA | (02h 40m 44.681s , -30d 04m 44.85s) | C | 180 | 18.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25610 SUBJECT: LIGO/Virgo S190901ap: Upper limits from Fermi-GBM Observations DATE: 19/09/02 05:11:21 GMT FROM: C. Michelle Hui at MSFC/Fermi-GBM C. M. Hui (NASA/MSFC) reports on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group For S190901ap and using the initial bayestar skymap, Fermi-GBM was observing 61% 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 S190901ap (GCN 25606). 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=112.4, Dec=-9.7 with a radius of 67.2 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: 3.0 5.0 9.9 1.024 s: 0.9 1.5 3.5 8.192 s: 0.4 0.5 0.9 Assuming the median luminosity distance of 242 Mpc from the GW detection, we estimate the following intrinsic luminosity upper limits over the 1 keV-10 MeV energy range (in units of 10^48 erg/s): Timescale Soft Normal Hard ------------------------------------ 0.128 s: 3.2 5.0 16.2 1.024 s: 1.0 1.5 5.7 8.192 s: 0.4 0.5 1.5 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25611 SUBJECT: LIGO/Virgo S190901ap : no neutrino counterpart candidate in ANTARES search DATE: 19/09/02 06:46:23 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 S190901ap event using the 90% contour of the Initial bayestar probability map provided by the GW interferometers (GCN#25606 ). 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/S190901ap_Initial.png . Considering the location probability provided by the LIGO/Virgo collaborations, there is a 54.1% 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 2019-09-01 23:31:01 and in the 90% contour of the S190901ap event. The expected number of atmospheric background events in the region visible by ANTARES is 4.34e-03 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 3.12e-02 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: 25612 SUBJECT: LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations DATE: 19/09/02 07:32:02 GMT FROM: Motoko Serino at RIKEN/MAXI M. Serino, S. Sugita (AGU), H. Negoro (Nihon U.), N. Kawai, M. Sugizaki (Tokyo Tech), M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), T. Mihara, 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, N. Isobe, 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) report on behalf of the MAXI team: We examined MAXI/GSC all-sky X-ray images (2-20 keV) after the LVC trigger S190901ap at 2019-09-01 23:31:01.837 UTC (GCN #25606). At the trigger time of S190901ap, 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 4-orbit (360 min) observation with GSC after the event covered 72% of the 90% credible region of the bayestar skymap from 23:31:01 to 05:30:56 UTC (T0+0 to T0+21595 sec). No significant new source was found in the region in the 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: 25613 SUBJECT: LIGO/Virgo S190901ap: No counterpart candidates in AGILE-MCAL observations DATE: 19/09/02 08:16:12 GMT FROM: Martina Cardillo at INAF-IAPS M. Cardillo (INAF/IAPS), F. Verrecchia (SSDC,and INAF/OAR), F. Longo (Univ. Trieste, and INFN Trieste), C. Pittori, F. Lucarelli (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini, G. Piano, A. Ursi (INAF/IAPS), A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), report on behalf of the AGILE Team: In response to the LIGO/Virgo GW event S190901ap at T0 = 2019-09-01 23:31:01 (UT), a preliminary analysis of the AGILE minicalorimeter (MCAL) triggered data found no event candidates within a time interval covering -/+ 15 sec from the LIGO/Virgo T0. At the T0, about 60% of the S190901ap 90% c.l. localization region was accessible to the AGILE MCAL.Three-sigma upper limits (ULs) are obtained for a 1 s integration time at different celestial positions within the accessible S190901ap localization region, from a minimum of 1.31E-06 erg cm^-2 to a maximum of 7.28E-06 erg cm^-2 (assuming as spectral model a single power law with photon index 1.5). The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25614 SUBJECT: LIGO/Virgo S190901ap: Updated Sky Localization DATE: 19/09/02 12:05:35 GMT FROM: Peter Shawhan at U of Maryland/LSC The LIGO Scientific Collaboration and the Virgo Collaboration report: We have conducted further analysis of the LIGO Livingston Observatory (L1) and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S190901ap (GCN Circular 25606). Parameter estimation has been performed using LALInference [1] and a new sky map, LALInference.v2.fits.gz, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S190901ap/ The preferred sky map at this time is LALInference.v2.fits.gz. For the LALInference.v2.fits.gz sky map, the 90% credible region is 14753 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 241 +/- 79 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] Veitch et al. PRD 91, 042003 (2015) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25616 SUBJECT: LIGO/Virgo S190901ap: Candidates from the Zwicky Transient Facility DATE: 19/09/02 14:32:28 GMT FROM: Mansi M. Kasliwal at Caltech/Carnegie Erik Kool (OKC), Robert Stein (DESY), Yashvi Sharma (Caltech), Viraj Karambelkar (Caltech), Mansi Kasliwal (Caltech), Daniel Perley (LJMU), Valery Brinnel (HU Berlin), Jakob Nordin (HU Berlin), Shreya Anand (Caltech), Michael Coughlin (Caltech), Leo P. Singer (NASA GSFC), Igor Andreoni (Caltech), Gaurav Waratkar (IITB), Harsh Kumar (IITB), Maitreya Khandagale (IITB), Kunal Deshmukh (IITB), Varun Bhalerao (IITB), G. C. Anupama (IIA), Dougal Dobie (USyd/CSIRO), Brad Cenko (NASA GSFC), Tomas Ahmuda (UMD), Eric Bellm (UW), Albert Kong (NTHU), Anna Franckowiak (DESY), Pradip Gatkine (UMD) On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations We observed the localization region of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614) with the Palomar 48-inch telescope equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). The tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). We started obtaining target-of-opportunity observations in the g-band and r-band beginning at UT 2019-09-02 03:08 UT. We covered 44% of the enclosed probability based on the new lalinference map (38% of the enclosed probability based on the initial bayestar map) in 6500 sq deg mapped before we had to close due to clouds. Each exposure was 30s with a typical depth of 20.7 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to search the alerts database for candidates. After rejecting stellar sources (Tachibana and Miller 2018) and moving objects and applying machine learning algorithms (Mahabal et al. 2019), and after removing candidates with history of variability prior to the merger time, the following high-significance transient candidates were identified by our pipeline in the 95% localization of the new lalinference map (LVC et al. GCN 25614). ------------------------------------------------------------------------ ZTF Name | RA (deg) | DEC (deg) | Filter | Mag | Magerr ------------------------------------------------------------------------ ZTF19abvizsw | 279.472820 | +61.497984 | r | 19.45 | 0.11 ZTF19abvixoy | 279.552972 | +27.420935 | r | 19.22 | 0.10 ZTF19abvjnsm | 267.202697 | +44.693203 | r | 20.23 | 0.20 ZTF19abvionh | 253.750924 | +14.051330 | g | 20.73 | 0.31 ------------------------------------------------------------------------ ZTF19abvizsw has a red color (g-r ~ 0.5 mag), no underlying host in the reference image and is on the outer periphery of the new LVC sky localization. ZTF has observed this field every night for the past month as part of routine survey operations and the first detections of this transient are only after the binary neutron star merger time. ZTF19abvixoy has an upper limit from Aug 30 UT and possibly a faint counterpart in PS1. ZTF19abvjnsm has an upper limit from Sep 1 UT but its host galaxy has too high a phot-z estimate from SDSS of 0.51 +/- 0.11. The host galaxy of ZTF19abvionh has a consistent SDSS phot-z (0.064 +/- 0.016) but the two detections last night are separated by only a short baseline of 7 minutes (a moving object in our solar system cannot be ruled out for this candidate). We encourage spectroscopic and photometric follow-up to discern the nature of these transients. ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering and follow-up co-ordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25617 SUBJECT: LIGO/Virgo S190901ap: no counterpart candidates in the Swift/BAT Observations DATE: 19/09/02 16:06:35 GMT FROM: Amy Lien at GSFC D. M. Palmer (LANL), S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC), 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-SSDC), S. Emery (UCL-MSSL), P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU), D. Hartmann (Clemson U.), J. A. Kennea (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 (Uni. of Warwick), 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 (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 S190901ap (LIGO/VIRGO Collaboration GCN Circ. 25606), where T0 is the LVC trigger time (2019-09-01T23:31:01.837 UTC). The center of the BAT field of view (FOV) at T0 is RA = 154.887 deg, DEC = -39.451 deg, and the roll angle is 7.936 deg. The BAT FOV (>10% partial coding) covers 2.70% of the integrated LVC localization probability, and 2.64% 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 ~ 1.39 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 ~ 60.86 Mpc. Event data is available from T0-50.369 to T0-47.257. No significant detections are found in the 15-350 keV images created using this event data interval. BAT retains decreased, but significant, sensitivity to rate increases for gamma-ray events outside of its FOV. About 76.67% 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/S190901ap/web/source_public.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25618 SUBJECT: LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvizsw DATE: 19/09/02 23:07:12 GMT FROM: Lina Tomasella at INAF,Padova I. Salmaso, L. Tomasella, S. Benetti (INAF Padova), P. D’Avanzo (INAF Brera), E. Cappellaro (INAF Padova), M.T. Botticella (INAF Napoli), R. Martone (Ferrara University), A. Rossi (INAF Bologna), E. Brocato (INAF Teramo), on behalf of GRAWITA report: We used the Asiago 1.82m Copernico telescope equipped with the AFOSC spectrograph and camera to observe one of the candidate transient found by the Zwicky Transient Facility (ZTFabvizsw; Kool et al. GCN 25616) localized in the region of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614). Optical images were obtained with the uBVgriz filters. Two optical spectra (1800s, 2400s exposure time) were obtained using the grism gr4 (wavelength range ~ 340-820 nm, resolution 1.4 nm). The spectrum is typical of a Galactic K or M star. Thus it could be a Galactic variable, although a rarer case of stellar microlensing event could not be excluded (see Benetti et al. 1995, Astron. Astrophys. Letters, 294, L37). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25619 SUBJECT: LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvixoy DATE: 19/09/03 00:36:22 GMT FROM: Lina Tomasella at INAF,Padova I. Salmaso, L. Tomasella, S. Benetti (INAF Padova), P. D’Avanzo (INAF Brera), E. Cappellaro (INAF Padova), M.T. Botticella (INAF Napoli), R. Martone (Ferrara University), A. Rossi (INAF Bologna), E. Brocato (INAF Teramo), on behalf of GRAWITA report: We used the Asiago 1.82m Copernico telescope equipped with the AFOSC spectrograph and camera to observe the candidate transient found by the Zwicky Transient Facility ZTFabvixoy (Kool et al. GCN 25616) localized in the region of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614). The optical spectrum (2700s exposure time) was obtained using the grism gr4 (wavelength range ~ 340-820 nm, resolution 1.4 nm) and it is characterized by a strong blue continuum. There is a weak Halpha emission, at rest wavelength, surrounded by broad absorption troughs. The emission core inside Hbeta and Hgamma absorption is only perceptible, while higher Balmer lines are in pure absorption. The object is likely a CV. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25620 SUBJECT: LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of target galaxy; no obvious optical counterpart. DATE: 19/09/03 00:41:40 GMT FROM: J. Craig Wheeler at U.Texas Austin M. J. B. Rosell, Sergey Rostopchin and Aaron Zimmerman, on behalf of the LIGO Hobby-Eberly Telescope Response (LIGHETR) team, report the spectroscopic observation of the field of S190901ap (GCN #24208) with the VIRUS IFU array. We took observations on our most likely target within a list of galaxies from the GLADE catalog that overlapped with the LIGO probability map and the observable pupil of the HET. The resulting data cube covers the wavelength 350 to 550 nm with a resolving power of 750. The effective limiting magnitude in the B band was 22 magnitudes. The field is 50x50 arc seconds. We observed the galaxy: GW65.490150+1.838955 04:21:57.636 +01:50:20.24 A more detailed report of the results will be submitted later. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25622 SUBJECT: LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh DATE: 19/09/03 05:05:39 GMT FROM: J. Craig Wheeler at U.Texas Austin M. J. B. Rosell, Karl Gebhardt, Aaron Zimmerman, Matthew Shetrone, Chris Fryer, J. Craig Wheeler, Steve Odewahn, and Nathan McReynolds on behalf of the LIGO Hobby-Eberly Telescope Response (LIGHETR) team, report the spectroscopic observation of the candidate optical transient ZTF19abvionh(GCN #25616) in the field of S190901ap (GCN #24208). The observations cover the wavelength range of 3500 to 5500 Angstroms. We detect a nearly featureless continuum peaking at about 4500 Angstroms. There are emission lines at about 4124 Angstroms and 5370 Angstroms that probably correspond to [O II] 3727 and Hbeta at a redshift of ~0.1. These emission lines are likely to be associated with nearby galaxy GALEXASC J165500.03+140301.3. The image of the target object falls within the extent of this galaxy. The distance corresponding to this redshift is 450 Mpc, about 2.5 sigma more than the estimated distance of the merger candidate. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25624 SUBJECT: LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh [correction on the peak] DATE: 19/09/03 05:50:14 GMT FROM: Maria Jose Bustamante Rosell at UT Austin M. J. B. Rosell, Karl Gebhardt, Aaron Zimmerman, Matthew Shetrone, Chris Fryer, J. Craig Wheeler, Steve Odewahn, and Nathan McReynolds on behalf of the LIGO Hobby-Eberly Telescope Response (LIGHETR) team. After further calibrations, we report the nearly featureless spectrum reported in GCN CIRCULAR 25620 does not peak at about 4500 A but further in the blue, rising towards 3500 A, the limit of our wavelength range. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25625 SUBJECT: LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations DATE: 19/09/03 07:30:15 GMT FROM: Magnus Axelsson at Stockholm U. M. Axelsson (KTH and Stockholm Univ.), F. Piron (CNRS/IN2P3/LUPM), L. Scotton (University and INFN, Torino), F. Longo (University and INFN, Trieste) and E. Bissaldi (Politecnico and INFN Bari) report on behalf of the Fermi-LAT Collaboration: We have searched data collected by the Fermi Large Area Telescope (LAT) on Sep 1, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger S190901ap (GCN 25606). 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 instantaneous coverage of 37% of the LIGO probability region at the time of the trigger (T0 = 2019-09-01 23:31:01.838 UTC), and reached 98% cumulative coverage after ~5 ks. The remaining area was not observed within 10 ks following the trigger time of the event. We performed a search for a transient counterpart within the observed region of the 90% contour of the LIGO map in a fixed time window from T0 to T0 + 10 ks. No significant sources were 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 5E-08 and 3E-07 [erg/cm^2/s]. The Fermi-LAT point of contact for this event is Lorenzo Scotton (lorenzo.scotton@to.infn.it). 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: 25626 SUBJECT: LIGO/Virgo S190901ap: No neutrino candidates at Pierre Auger Observatory DATE: 19/09/03 09:00:45 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: LIGO/Virgo GW trigger S190901ap T0=2019-09-01 23:31:01 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 S1900901ap 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 PARTIALLY COINCIDENT (38.7%) with the LIGO/Virgo 90% localization region (LALInference.v2.fits.gz) at the time T0 of the merger alert, achieving MAXIMUM OVERLAP (47.7%) at approximately T0+17.2 hours ------- 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 https://arxiv.org/abs/1906.07422 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25630 SUBJECT: LIGO/Virgo S190901ap: Upper limits from AGILE-GRID observations DATE: 19/09/03 14:32:13 GMT FROM: Martina Cardillo at INAF-IAPS M. Cardillo (INAF/IAPS), F. Verrecchia (SSDC,and INAF/OAR), F. Longo (Univ. Trieste, and INFN Trieste),C. Pittori, F. Lucarelli (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS and Univ. Roma Tor Vergata),C. Casentini, G. Piano, A. Ursi (INAF/IAPS),A. Bulgarelli, V. Fioretti,N. Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), report on behalf of the AGILE Team: In response to the LIGO-Virgo GW event S190901ap at T0 = 2019-09-01 23:31:01.838 UTC a preliminary analysis of the AGILE exposure at T0 shows that the Gamma-Ray Imaging Detector (GRID) exposure covered about 20% of the 90% c.l. localization region (LR) (13% of 90% c.l. localization region (LR) is occulted by Earth). We performed an analysis of the GRID data in the energy range 50 MeV - 10 GeV on T0, where good exposure of the S190901ap 90% c.l. LR was available. No candidate gamma-ray transient was detected. The following preliminary GRID values of 3-sigma upper limit (UL) are obtained: from 3.00e-07 to 9.32e-06 erg cm^-2 s^-1, with exposure of about 16% of the LR over the time interval ( T0s ; T0 + 10s ); from 3.59e-08 to 6.91e-06 erg cm^-2 s^-1, with exposure of about 26% of the LR over the time interval ( T0s ; T0 + 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: 25632 SUBJECT: LIGO/Virgo S190901ap: GROWTH-India follow-up of ZTF19abvionh DATE: 19/09/03 16:40:09 GMT FROM: Gaurav Waratkar at IIT Bombay Harsh Kumar (IITB), Anirban Dutta (IIA), Gaurav Waratkar (IITB), Kunal Deshmukh (IITB), Maitreya Khandagale (IITB), Avinash Singh (IIA), Erik Kool (OKC), Varun Bhalerao (IITB), G. C. Anupama (IIA), Urgain Stanzin (IIA) report on behalf of the GROWTH collaboration: We observed the optical counterpart candidate ZTF19abvionh (Erik Kool et al. GCN 25616, M. J. B. Rosell et al. GCN 25622, GCN 25624) of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614) with the 0.7m GROWTH-India telescope. We obtained a series of exposures, each 600 sec long, in SDSS-r filter starting from 2458729.15950926 JD. We used PS1 catalog images for image subtraction. The candidate was clearly detected in the subtracted images. Photometry of the subtracted images is reported below: ------------------------------------------------------------------ JD(Start) | Name | Filter | Mag | Mar_err| ------------------------------------------------------------------ 2458729.15950926 | ZTF19abvionh | r | 20.81 | 0.117 2458729.16622148 | ZTF19abvionh | r | 20.83 | 0.088 2458729.20642199 | ZTF19abvionh | r | 20.56 | 0.108 2458729.21345010 | ZTF19abvionh | r | 20.50 | 0.088 ------------------------------------------------------------------ Our measurements indicate a rise in the r-band brightness of the candidate. Further observations are planned. We encourage further monitoring of this candidate. The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25634 SUBJECT: LIGO/Virgo S190901ap: Additional observations from the Zwicky Transient Facility DATE: 19/09/03 19:26:03 GMT FROM: Robert Stein at DESY Robert Stein (DESY), Erik Kool (OKC), Viraj Karambelkar (Caltech), Mansi Kasliwal (Caltech), Daniel Perley (LJMU), Shreya Anand (Caltech), Michael Coughlin (Caltech), Yashvi Sharma (Caltech), Leo P. Singer (NASA GSFC), Igor Andreoni (Caltech), Gaurav Waratkar (IITB), Harsh Kumar (IITB), Maitreya Khandagale (IITB), Kunal Deshmukh (IITB), Varun Bhalerao (IITB), G. C. Anupama (IIA), Dougal Dobie (USyd/CSIRO), Brad Cenko (NASA GSFC), Tomas Ahmuda (UMD), Eric Bellm (UW), Albert Kong (NTHU), Anna Franckowiak (DESY), Pradip Gatkine (UMD) On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We again observed the localization region of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614) with the Palomar 48-inch telescope equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). The tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). We started our new target-of-opportunity observations in the g-band and r-band beginning at UT 2019-09-03 03:12 UT. Each exposure was 30s, and due to poor weather images had a typical median depth of 19.5 mag. Moreover, the planned observations were not completed due to dome closure. Between the two nights of observations, we have covered 48% of the enclosed probability based at least once, and 35% of the enclosed probability at least twice. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to search the alerts database for candidates. We rejected stellar sources (Tachibana and Miller 2018) and moving objects and applying machine learning algorithms (Mahabal et al. 2019), and removed candidates with history of variability prior to the merger time. One additional object was found by our pipeline, detected twice on our first night of observations (Kool et al. GCN 25616). ------------------------------------------------------------------------ ZTF Name | RA (deg) | DEC (deg) | Filter | Mag | Magerr ------------------------------------------------------------------------ ZTF19abvitlr | 279.200304 | -11.579390 | r | 18.89 | 0.08 ------------------------------------------------------------------------ ZTF19abvitlr is a red transient located in a crowded stellar field at galactic latitude of -2 deg, and was not detected in observations on Aug 30 to a depth of 20.1 mag. It is significantly offset from the nearest PS1 source, and has a steep lightcurve rise. Given these properties it is likely a reddened galactic Cataclysmic Variable. Spectroscopic follow-up would confirm the nature of this transient. ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd,Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering and follow-up co-ordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25638 SUBJECT: LIGO/Virgo S190901ap: Keck I LRIS spectroscopy of ZTF19abvionh DATE: 19/09/04 00:26:12 GMT FROM: Mansi M. Kasliwal at Caltech/Carnegie Kevin Burdge (Caltech), Mansi M. Kasliwal (Caltech), Daniel A. Perley (LJMU) report on behalf of the GROWTH collaboration We obtained a Keck I LRIS spectrum of ZTF19abvionh (Kool et al. GCN 25616). We see a hot, blue continuum and host galaxy lines at z=0.0985. The corresponding luminosity distance of 456 Mpc is inconsistent with the GW constraints on S190901ap (LVC et al. GCN 25614, GCN 25606) suggesting this could evolve into a young supernova. Our conclusions are broadly consistent with Rossell et al. GCN 25622. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25639 SUBJECT: LIGO/Virgo S190901ap: Keck I LRIS spectroscopy of ZTF19abvizsw DATE: 19/09/04 00:27:15 GMT FROM: Mansi M. Kasliwal at Caltech/Carnegie Kevin Burdge (Caltech), Daniel A. Perley (LJMU) and Mansi M. Kasliwal (Caltech) report on behalf of the GROWTH collaboration: We obtained a Keck I LRIS spectrum of ZTF19abvizsw (Kool et al. GCN 25616). The reduced spectrum shows a featureless continuum superimposed with a number of narrow absorption lines, including Mg II, Mg I, and Fe II at a consistent redshift of z=1.26. This is far beyond the GW distance constraints on S190901ap (LVC et al. GCN 25614, GCN 25606) and demonstrates that this source is unrelated to the LIGO/Virgo source. It could be a flaring AGN or blazar, but there is no counterpart in PS1 or WISE and only a dim, marginal object at this location in the Legacy Survey. It may also be a GRB afterglow. Our conclusions disagree with those of Salmaso et al. (GCN 25618), who reported an M- or K-dwarf spectrum for this object. We note that there is a bright, red star less than 2 arcsec away from the transient position and it is possible that the spectrum reported in GCN 25618 may correspond to that object. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25640 SUBJECT: LIGO/Virgo S190901ap : SVOM/GWAC-F60A observation of transient ZTFabvizsw DATE: 19/09/04 01:42:35 GMT FROM: Liping Xin at NAOC, SVOM J. Y. Wei (NAOC), L. P. Xin (NAOC), S. Antier (CNRS/APC), J. Wang (GXU), N. Leroy (CNRS/LCL), D. Turpin (NAOC) on behalf of the SVOM Multi Messenger Astronomy and GWAC teams: http://www.svom.fr/en/svom-mma-and-gwac-team We used the 60cm SVOM/GWAC-F60A telescope to observe the transient found by the Zwicky Transient Facility ZTF19abvizsw (Kool et al. GCN 25616) localized in the region of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614) during 17:28:07 and 18:45:07 UT on 02th, Sep. 2019. After stacking the images for 31*150 sec, the source was detected with a brightness of R=20.53+/-0.16 mag calibrated by nearby USNO R2 magnitudes. Comparing with the reported by Kool et al., GCN 25616, the source was fading for about one magnitude. Considering its fast decay, a featureless continuum superimposed with a number of narrow absorption lines and the large distance of z=1.26 (Burdge et al., GCN 25639), it is possible an orphan GRB afterglow. The stacked image observed by GWAC-F60A is shown here, http://cmm.svom.cn/gwpub/O3/S190901ap/ZTF19abvizsw_F60_findingchart.png (user:svomo3 pwd:gwo3) SVOM/GWAC-F60A is a dedicated telescope for follow-ups of SVOM/GWAC system, and is operated by Guangxi university and NAOC, CAS, at Xinglong observatory, China. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25645 SUBJECT: LIGO/Virgo S190901ap: Upper limits from Insight-HXMT/HE observations DATE: 19/09/04 06:25:45 GMT FROM: Ce Cai at IHEP J. M. Yao, Y. G. Zheng, C. Cai, Q. Luo, S. Xiao, Q. B. Yi, Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: Insight-HXMT was taking data normally around the reported LIGO/Virgo S190901ap event (GCN #25606), trigger time 2019-09-01T23:31:01.838 UTC. At T0, about 61% of the LIGO localization region was covered by the Insight-HXMT without occultationby the Earth. Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are found in a search of the Insight-HXMT/HE raw light curves. Assuming the GW counterpart GRB with three typical GRB Band spectral models, two typical duration timescales (1 s, 10 s) from the center of the LIGO-Virgo location probability map (RA=57 deg, DEC=-21 deg), the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are reported below: Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV): 1 s: 7.7e-08 erg cm^-2 10 s: 1.3e-07 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1 s: 1.4e-07 erg cm^-2 10 s: 2.7e-07 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1 s: 3.7e-07 erg cm^-2 10 s: 2.9e-06 erg cm^-2 All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the spacecraft. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information could be found at: http://www.hxmt.org. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25647 SUBJECT: LIGO/Virgo S190901ap: Upper limits from CALET observations. DATE: 19/09/04 07:06:55 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 S190901ap T0 = 2019-09-01 23:31:01.838 UT (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 25606 and 25614). 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 6 % and 61 %, respectively (and 82 % credible region of the updated localization map was above the horizon). The HXM and SGM fields of view were centered at RA = 345.1 deg, Dec = 22.4 deg and RA = 353.8 deg, Dec = 16.7 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 (signal-to-noise ratio >= 7) around the trigger time in either the HXM or the SGM data. The CALET Calorimeter (CAL) was operating in the low energy trigger mode at the trigger time of S190901ap. Using the CAL data, we have searched for gamma-ray events in the 1-10 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 probability map. The 90% upper limit of CAL is 6.3x10^-5 erg/cm^2/s (1-10 GeV) when the summed LIGO-Virgo probability reaches 5%. The CAL FOV was centered at RA= 353.8 deg, Dec= 16.6 deg at T0. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25648 SUBJECT: LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations DATE: 19/09/04 08:21:17 GMT FROM: Xuhui Han at NAOC/SVOM J. Y. Wei (NAOC), X. H. Han (NAOC), S. Antier (CNRS/APC), J. Wang (GXU), N. Leroy (CNRS/LCL), L. P. Xin (NAOC) on behalf of the SVOM Multi Messenger Astronomy and GWAC teams: http://www.svom.fr/en/svom-mma-and-gwac-team We observed 23 sky regions (total: 3450 square degrees with overlaps) to cover the skymap of the advanced LIGO/Virgo trigger S190901ap, with SVOM/GWAC, at Xinglong Observatory equipped with a set of two types of wide angle cameras: FFOV cameras (FOV~900 square degrees/camera, aperture = 3.5 cm) and JFOV cameras (FOV~150 square degrees/camera, aperture = 18 cm). SVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras, working with unfiltered band. The observations are operated in time-series mode, taking one exposure every 25 seconds (20s exposure + 5s readout). We estimate a 21.1% prior probability that the 23 observed and processed regions contain the true location of the source. The images were taken between ~12 hours and ~21 hours after the event trigger time. The coordinates of the 23 sky regions and observation times are listed below: No. Ra Dec start-obs(UTC) end-obs(UTC) Camera_TYPE 1 14:52:45.36 36:27:42.12 2019-09-02 11:50:35 2019-09-02 12:57:50 JFOV 2 14:47:05.52 48:27:28.80 2019-09-02 12:52:10 2019-09-02 12:57:50 JFOV 3 16:04:10.80 30:49:03.00 2019-09-02 11:41:44 2019-09-02 11:47:24 JFOV 4 15:09:00.24 18:30:39.60 2019-09-02 11:50:38 2019-09-02 11:54:17 JFOV 5 15:07:09.12 30:35:42.36 2019-09-02 11:50:39 2019-09-02 11:54:17 JFOV 6 15:26:18.24 15:16:59.88 2019-09-02 13:08:45 2019-09-02 13:26:57 JFOV 7 16:02:03.12 35:25:58.44 2019-09-02 13:05:29 2019-09-02 13:21:17 JFOV 8 16:39:42.96 27:17:34.80 2019-09-02 12:08:56 2019-09-02 12:23:06 JFOV 9 01:16:21.62 -15:31:53.40 2019-09-02 16:24:34 2019-09-02 16:52:31 JFOV 10 17:19:00.24 52:14:09.60 2019-09-02 14:45:41 2019-09-02 14:56:13 JFOV 11 18:05:18.24 01:30:15.52 2019-09-02 13:51:32 2019-09-02 13:52:21 JFOV 12 02:28:14.83 -15:30:36.00 2019-09-02 17:27:23 2019-09-02 19:01:31 JFOV 13 03:19:23.62 -3:14:21.77 2019-09-02 17:31:26 2019-09-02 17:52:54 JFOV 14 03:58:00.72 -1:57:11.38 2019-09-02 17:34:35 2019-09-02 17:49:09 JFOV 15 03:41:15.24 01:27:46.30 2019-09-02 18:01:48 2019-09-02 18:22:04 JFOV 16 04:31:50.62 13:46:42.60 2019-09-02 18:01:48 2019-09-02 18:14:22 JFOV 17 04:08:53.54 15:03:23.04 2019-09-02 16:59:48 2019-09-02 20:27:27 JFOV 18 04:44:53.30 35:53:54.24 2019-09-02 18:04:30 2019-09-02 18:21:05 JFOV 19 04:53:17.66 01:30:11.16 2019-09-02 19:14:43 2019-09-02 20:04:18 JFOV 20 05:43:52.15 13:49:17.40 2019-09-02 19:22:00 2019-09-02 19:53:46 JFOV 21 04:52:20.66 -15:27:02.16 2019-09-02 20:16:15 2019-09-02 20:35:42 JFOV 22 05:43:23.81 -3:10:38.86 2019-09-02 20:26:22 2019-09-02 20:35:42 JFOV 23 05:24:02.42 14:49:40.80 2019-09-02 18:40:24 2019-09-02 18:52:32 JFOV The sky coverage map is available at: http://cmm.svom.cn/gwpub/O3/S190901ap/S190901ap.png (user:svomo3 pwd:gwo3) The weather condition was clear during the observations. A 3 sigma limiting magnitude of about 16.3 mag in R band was obtained in the single frames. No credible new source is 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: 25649 SUBJECT: LIGO/Virgo S190901ap: MASTER OT J171434.95+280725.6/AT2019pjv detection DATE: 19/09/04 08:42:33 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, T.Pogrosheva, E. Gorbovskoy, F.Balakin, V.Kornilov, N.Tyurina, P.Balanutsa,A.Kuznetsov, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, A.Chasovnikov,V.Topolev, A.Posdnyakov(Lomonosov Moscow State University, SAI, Physics Department), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), 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), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), MASTER Global Robotic Net ( http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) started LIGO/Virgo S190901ap error-box (LVC GCN 25606) alert and inspect observations at 2019-09-02 01:42:16 UT (Lipunov et al GCN 25609). During inspection we found OT, that can be assotiated with known PGC059913 (distance ~ 100Mpc, Btot=15.7), see image. OT offset are 44W 10.8N arcsec. MASTER OT J171434.95+280725.6 discovery - possibly LVC S190901ap optical counterpart. MASTER-IAC auto-detection system discovered OT source at (RA, Dec) = 17h 14m 34.95s +28d 07m 25.6s on 2019-09-03.97890 UT. The OT unfiltered magnitude is 18.9m (limit 19.7m). The OT is seen in 2 inspect images. There is no minor planet at this place. We have reference image without OT on 2015-09-15.93950 UT with unfiltered magnitude limit 20.4m. Spectral observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/171434.95280725.6.png This OT is in TNS as AT2019pjv //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25650 SUBJECT: LIGO/Virgo S190901ap : GRAWITA photometric observation of candidate ZTFabvizsw and GCN 25618 revision DATE: 19/09/04 08:57:51 GMT FROM: Lina Tomasella at INAF,Padova I. Salmaso, L. Tomasella, S. Benetti (INAF Padova), P. D’Avanzo (INAF Brera), E. Cappellaro (INAF Padova), M.T. Botticella (INAF Napoli), R. Martone (Ferrara University), A. Rossi (INAF Bologna), E. Brocato (INAF Teramo), on behalf of GRAWITA report: Following Burdge et al. (GCN 25639) we revised our results published in Salmaso et al. (GCN 25618). The average seeing of Salmaso et al. frames was around 2.5-3 arcsec and ZTF19abvizsw was barely visible in a single 60 sec long exposure, while a nearby brighter star (at R.A.= 18:37:53.50, decl=+61:29:45.96) had a magnitude g=19.52+/-0.04 close to that reported by Kool et al. in GCN 25616 for ZTF19abvizsw. Therefore we indeed took erroneously the spectrum of the nearby star which is clearly unrelated to the gravitational wave trigger S190901ap. ZTF19abvizsw stands clearly out in our best seeing frames and the preliminary magnitudes we measure are the following (Time gives the UT start): Time (UT) filter mag(AB) err ————————————————— 2019-09-02 20:56:48 g 20.77 0.11 2019-09-02 20:57:58 r 20.54 0.12 2019-09-02 20:59:07 i 20.25 0.15 2019-09-02 21:00:17 z 20.65 0.15 The transient is fading rapidly in agreement with the finding of Perley et al. (CGN 25643). We regret for any trouble this may have caused. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25653 SUBJECT: LIGO/Virgo S190901ap: GTC follow-up spectroscopic observations of ZTF19abvizsw DATE: 19/09/04 11:44:44 GMT FROM: Peter Jonker at SRON/RU A.J. Levan (Radboud), P.G. Jonker (SRON/Radboud), P. Rodriguez Gil, M.A.P. Torres (IAC/ULL), K. Maguire (TCD), M. Fraser (UCD), D. Mata (JBCA, University of Manchester) report on behalf of a larger collaboration: We obtained 3x900 sec of spectroscopic observations of ZTF19abvizsw with the GTC on La Palma on 2 September 2019 over the time interval 20:37 - 22:05 UT using the R1000R grating and the OSIRIS instrument. The spectra cover the range 5100-10000 AA. A strong continuum is detected with prominent absorption lines which we identify as FeII (2344, 2374, 2383, 2586, 2600 AA) and MgII (2796, 2803 AA) and MgI (2852 AA) at a common redshift of z=1.258. This is in agreement with the results of Burdge et al. (GCN 25639). Indeed the spectral features provide a good match to the composite spectra of GRB afterglows (Christensen et al. 2011). This offers further support for the identification of ZTF19abvizsw as an untriggered GRB (Perley et al. GCN 25643). Searches in existing gamma-ray observations around the rise time would be strongly merited. We thank the GTC staff and especially Peter Pessev for their assistance in acquiring these observations. Acknowledgements: PGJ acknowledges support from the European Research Council under ERC Consolidator Grant agreement no 647208. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25654 SUBJECT: LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv DATE: 19/09/04 13:39:34 GMT FROM: Danny Steeghs at U.of Warwick/GOTO K.Ackley(2), D.Mata-Sanchez(8), Y-L.Mong(2), R.Cutter(1), K.Ulaczyk(1), J.Lyman(1), D.Steeghs(1), G.Ramsay(5), D.Galloway(2), L.Makrygianni(3), M.Kennedy(8), A.Obradovic(2), M.Dyer(3), V.Dhillon(3), P.O'Brien(4), D.Pollacco(1), E.Thrane(2), S.Poshyachinda(6), E.Palle(7), K.Wiersema(1), T. Marsh(1), R.West(1), B.Gompertz(1), E.Stanway(1), A.Casey(2), M.Brown(2), E.Rol(2), J.Mullaney(3), S.Littlefair(3), E.Daw(3), J.Maund(3), R.Starling(4), R.Eyles(4), S.Tooke(4), U.Sawangwit(6), D.Mkrtichian(6), S.Awiphan(6), S.Aukkaravittayapun(6), P.Irawati(6), R.Breton(8), T.Heikkila(9), R.Kotak(9), L.Nuttall (10) (1) Warwick University; (2) Monash University; (3) Univ. of Sheffield; (4) University of Leicester; (5) Armagh Observatory & Planetarium; (6) National Astronomical Research Institute of Thailand; (7) Instituto de Astrofisica de Canarias; (8) Univ. of Manchester; (9) University of Turku; (10) University of Portsmouth report on behalf of the GOTO collaboration: We report on observations with the Gravitational-wave Optical Transient Observer (GOTO) on La Palma, Canary Islands, in response to the LIGO/Virgo gravitational wave event S190901ap, triggered 2019-09-01 23:31:01.838 UTC (GCN #25606). We performed a series of 3x60s exposures using a wide (400-700nm passband) L-band filter with a typical 5-sigma photometric depth equivalent to g~20 based on a photometric calibration against PS1 sources. Observations commenced on 2019-09-01 23:37:46 UT (6.7 min post-trigger) and continued through 2019-09-04 05:45:10 UT. In total we covered 2507 square degrees containing ~28.2% of the total source location probability (based on the skymap at https://gracedb.ligo.org/api/superevents/S190901ap/files/bayestar.fits .gz) across 162 tiles. The median number of visits per tile was 3, with some tiles visited up to 18 times. Images are processed immediately after acquisition using the GOTOphoto pipeline. Difference imaging was performed on the median of each triplet of exposures using recent survey observations of the same pointings, which were available for 88% of our tiles. Source candidates were initially filtered using a trained classifier and cross-matched against a variety of catalogs, including the MPC and PS1. Human candidate vetting was performed on those candidates identified by the classifier. No additional viable optical counterpart candidates beyond those already reported were identified. We detected AT2019pjv (Lipunov et al. GCN #25649) as a rising transient. The source rose above our detection limit on Sept 2nd, with internal designation GOTO2019hope, and no source was detected at this position during a series of observations preceding the GW event (most recent visit pre-trigger 2019-08-06). We provide the following preliminary magnitudes: DATE: MAG: 2019-08-06.9 >20 2019-09-01.9 > 20 2019-09-02.9 ~ 19.6 2019-09-03.9 19.0 ======= GOTO is operated at the La Palma observing facilities of the University of Warwick on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT) and the Instituto de Astrofisica de Canarias (IAC) (https://goto-observatory.org) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25656 SUBJECT: LIGO/Virgo S190901ap: Additional candidates from the Zwicky Transient Facility DATE: 19/09/04 15:35:38 GMT FROM: Robert Stein at DESY Robert Stein (DESY), Erik Kool (OKC), Harsh Kumar (IITB), Michael Coughlin (Caltech), Mansi Kasliwal (Caltech), Daniel Perley (LJMU), Shreya Anand (Caltech), Yashvi Sharma (Caltech), Viraj Karambelkar (Caltech), Leo P. Singer (NASA GSFC), Igor Andreoni (Caltech), Gaurav Waratkar (IITB), Maitreya Khandagale (IITB), Kunal Deshmukh (IITB), Varun Bhalerao (IITB), G. C. Anupama (IIA), Dougal Dobie (USyd/CSIRO), Brad Cenko (NASA GSFC), Tomas Ahmuda (UMD), Eric Bellm (UW), Albert Kong (NTHU), Anna Franckowiak (DESY), Pradip Gatkine (UMD) On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We again observed the localization region of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614) with the Palomar 48-inch telescope equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). The tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). We started our new target-of-opportunity observations in the g-band and r-band beginning at UT 2019-09-04 10:18 UT. Each exposure was 30s, with a typical median depth of 20.8 mag in g band and 20.6 mag in r band. Across the three nights of observations (Kool et al. GCN 25616, Stein et al. GCN 25634), we have covered 73% of the enclosed probability at least once, and 67% of the enclosed probability at least twice. This estimate does not account for chip gaps. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to search the alerts database for candidates. We rejected stellar sources (Tachibana and Miller 2018) and moving objects, applied machine learning algorithms (Mahabal et al. 2019), and removed candidates with history of variability prior to the merger time. Two additional candidates were found by our pipeline. ------------------------------------------------------------------------ ZTF Name | RA (deg) | DEC (deg) | Filter | Mag | Magerr ------------------------------------------------------------------------ ZTF19abwsmmd | 22.666409 | -19.712405 | r | 20.08 | 0.22 ZTF19abwvals | 73.250555 | +12.693030 | r | 19.83 | 0.19 ------------------------------------------------------------------------ ZTF19abwsmmd has a blue color (g - r ~ -0.25) and is located in a compact host galaxy with a SDSS photo z of ~0.05, consistent with the merger distance. It was not detected in g band on Aug 30 UT to a depth of 20.4 mag. ZTF19abwvals is red (g - r ~ 0.5), located in a host galaxy with an SDSS photo-z of ~0.13. It was not detected in g band on Sep 1 UT to a depth of 20.64. We encourage spectroscopic and photometric observations to discern the nature of these candidates. ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd,Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering and follow-up co-ordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25659 SUBJECT: LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv DATE: 19/09/04 16:53:06 GMT FROM: Dong Xu at NAOC/CAS B.Y. Yu, D. Xu, Z.P. Zhu, T.M. Zhang, X. Zhou, H.J. Wang, C.Z. Cui, D.W. Fan, Y.F. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), Z.B. Zhang (XJTS), S. Yang (Stockholm U.), H.B. Zhao, B. Li (PMO), J.Z. Liu, H.B. Niu (XAO), J.R. Mao, J.M. Bai (YNAO), report on behalf of the GWFUNC collaboration: We observed the optical transient AT2019pjv, a candidate of the optical counterpart of LIGO/Virgo S2019091ap (MASTER, Lipunov et al. GCN #25649; GOTO, Ackley et al., GCN #25654), using the Half Meter Telescope (HMT) located at Dabancheng, Xinjiang, China. Observations started at 14:31:01 UT on 2019-09-04, and 5x150 s unfiltered frames were obtained. The OT is clearly detected in each exposure, and we got m(r) = 18.00 +/- 0.05 mag in the stacked image, calibrated with nearby PanSTARRS field. In comparison with previous MASTER and GOTO measurements, the OT has been rising since its detection on Sep 2. Such behaviour is much more consistent with a young supernova than an optical afterglow of a short GRB or a kilonova. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25661 SUBJECT: LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate MASTER OT J171434.95+280725.6 DATE: 19/09/04 20:38:39 GMT FROM: Lina Tomasella at INAF,Padova V. Nascimbeni, I. Salmaso, L. Tomasella, S. Benetti (INAF Padova), P. D’Avanzo (INAF Brera), E. Cappellaro (INAF Padova), E. Brocato (INAF Teramo), on behalf of GRAWITA report: Under the Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841), we observed the candidate transient found by MASTER-IAC auto-detection system (Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L), announced in Atel # 13076 and GCN 25649, which is localized in the region of the gravitational wave trigger S190901ap (LVC et al. GCN 25606, GCN 25614). The optical spectrum was obtained with the Copernico 1.82m telescope equipped with Afosc spectrograph and grism #4 (wavelength range ~ 340-820 nm, resolution 1.4 nm). The best match is with Type Ia-91T like SNe about one week before maximum light. The redshift, as derived from SNID (Blondin and Tonry 2007, ApJ, 666, 1024), is z = 0.024, linking the transient to the host galaxy MCG+05-41-001 (z = 0.023 derived from the galaxy spectrum in SDSS, DR10). The transient is thus unrelated to the GW trigger S190901ap. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25663 SUBJECT: LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations DATE: 19/09/05 00:01:34 GMT FROM: Weikang Zheng at UC Berkeley Sergiy Vasylyev, Nachiket Girish, Thomas de Jaeger, Yukei Murakami, Benjamin E. Stahl, Keto D. Zhang, James Sunseri, Shaunak Modak, WeiKang Zheng, Andrew Hoffman, 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 S190901ap (GCN 25606; GCN 25614) 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 156 of them on Sep. 02 UT starting at 3.8 hours after the trigger, and additional 143 on Sep. 03 UT starting at 1.37 days after the trigger, according to their priority scores and elevation visibility, with each clear-filter exposure time being 60 s. 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. In addition, we took 7x180s clear band images of ZTF19abvizsw/AT2019pim (Kool et al., GCN 25616), now considered as an unrelated GRB optical afterglows candidate (Burdge et al., GCN 25639; Wei et al., GCN 25640; Perley et al., GCN 25643; Salmaso et al., GCN 25650; Levan et al., GCN 25653; Becerra et al., GCN 25655; Ho et al., GCN 25658). We estimate the clear band magnitude to be ~21.3 +/- 0.2 mag in our co-added image at Sep. 04.23 UT, calibrated to PS1 catalog. GladeID UT(Sep02) RA_J2000 Dec_J2000 ----------------------------------------------- G0194613 03:19:18 14:31:05.4346 +00:36:46.4688 G1875693 03:22:46 14:31:39.36 -00:17:11.94 G0603373 03:23:55 14:31:44.381 +00:48:42.7932 G1878039 03:25:04 14:32:14.88 +00:47:01.356 G1733195 03:26:14 14:32:41.52 +00:47:29.832 G0658315 03:27:23 14:32:48.7318 +02:04:41.9088 G0905344 03:28:32 14:32:53.1482 +01:32:24.414 G0740361 03:29:42 14:33:15.055 -00:49:28.992 G0663999 03:30:53 14:33:20.1562 +00:39:52.5492 G0307996 03:32:02 14:33:29.1614 +00:46:53.3316 G0757580 03:33:12 14:33:35.365 +00:54:26.3196 G0608391 03:34:23 14:33:36.7675 -01:05:05.6112 G0748622 03:35:32 14:33:44.8279 +00:47:42.3024 G0664011 03:36:42 14:33:57.2167 +00:35:10.8528 G0745915 03:37:53 14:34:09.0014 +01:37:00.8616 G1742502 03:39:07 14:34:13.92 +03:01:40.116 G0737461 03:40:16 14:34:23.7269 +02:23:31.038 G0783945 03:41:25 14:34:27.0667 +01:04:49.0404 G1278665 03:42:34 14:34:38.0712 +01:38:46.0392 G0756340 03:43:44 14:34:42.1363 +00:54:50.0364 G1742550 03:44:53 14:34:47.76 +02:02:28.536 G0713702 03:46:48 15:20:51.7932 -00:43:47.9316 G1224425 03:47:57 15:21:02.4096 -03:33:40.914 G0020414 03:49:07 15:21:08.7708 -07:20:45.6684 G1403147 03:50:16 15:21:15.9667 -10:11:20.67 G0838596 03:51:29 15:21:18.5669 -04:18:36.8172 G0917972 03:52:41 15:21:23.269 -12:04:38.2476 G0331855 03:53:50 15:21:33.2374 -08:49:50.6424 G1450425 03:54:59 15:21:34.6142 -08:04:07.6404 G1290735 03:56:09 15:21:48.6254 -06:14:40.0632 G0303133 03:57:18 15:22:05.8226 -05:28:59.1924 G0971203 03:58:29 15:23:07.3058 +01:25:40.9296 G1147715 03:59:43 15:23:59.0551 -10:49:57.8712 G0042791 04:00:54 15:24:16.7506 -05:46:36.102 G1109765 04:02:04 15:24:44.8205 -04:40:08.346 G1362904 04:03:13 15:25:47.7394 -06:52:10.0992 G0070527 04:04:22 15:25:51.7714 -01:53:01.3236 G1191119 04:05:33 15:26:42.9382 +00:13:14.7504 G1452726 04:06:44 15:27:11.8543 -08:35:42.1188 G0940632 04:07:53 15:27:14.6155 -04:44:00.51 G0936205 04:09:03 15:27:19.314 -05:19:06.5028 G1059447 04:10:14 15:28:06.6029 -11:12:38.5776 G0883642 04:11:25 15:29:02.5378 -05:34:13.152 G0928928 04:12:34 15:29:20.3357 -05:25:03.3528 G0906688 04:13:46 15:30:27.7735 -10:56:40.6788 G1388643 04:14:55 15:34:27.9749 -09:15:48.906 G0214088 04:16:06 15:34:42.9053 -04:14:22.6068 G1461463 04:17:18 15:35:15.2527 -09:24:21.5568 G1172917 04:18:27 15:36:50.2661 -06:06:55.4328 G0989502 04:19:36 15:37:52.2437 -07:12:55.4724 G0536188 04:20:48 15:24:40.177 -12:42:49.8276 G0566794 04:27:19 16:02:19.8449 +16:20:46.2552 G0395107 04:28:28 16:04:26.7298 +17:45:01.188 G0479641 04:29:38 16:05:44.5862 +16:12:11.8944 G0593543 04:30:47 16:06:22.8334 +19:46:40.2636 G0668634 04:31:56 16:06:42.0703 +16:19:11.154 G0657647 04:33:35 16:11:11.0083 +61:16:04.5444 G0627263 04:35:18 16:12:53.357 -21:37:24.0528 G0554714 04:36:44 16:13:04.9805 +30:54:05.994 G0684706 04:38:11 16:14:57.0154 +55:52:25.0428 G0789194 04:39:34 16:28:38.2764 +39:33:04.968 G0666910 04:40:54 16:32:57.2095 +50:24:05.1156 G0708649 04:42:20 16:34:25.4846 +21:32:27.0096 G0818453 04:43:46 16:43:23.1554 -24:52:47.0784 G0636473 04:45:10 16:45:26.4149 +18:12:30.3948 G0004443 04:46:33 16:49:03.6732 -17:38:45.3732 G0667530 04:47:42 16:49:21.0204 -17:38:40.326 G0628454 04:48:52 16:50:53.4228 -15:00:14.346 G0559558 04:50:01 16:52:07.7491 -17:03:13.518 G0609502 04:51:12 16:53:04.8559 -16:17:27.3552 G0788598 04:52:40 16:53:52.207 +39:45:36.9288 G0748918 04:54:05 16:54:08.7598 -07:38:07.314 G0613278 04:55:16 16:54:53.6462 -16:57:07.2756 G0771147 04:56:40 16:57:58.0994 +27:51:15.7248 G0644414 04:57:58 17:06:49.8048 +42:25:24.492 G0602659 04:59:23 17:10:50.4713 -06:30:43.0848 G0656855 05:00:33 17:11:14.9486 -05:21:58.3812 G0624001 05:01:42 17:12:33.2081 -05:35:26.7432 G0633958 05:02:55 17:18:54.0893 +08:26:26.9448 G1041639 05:04:19 17:20:15.6739 +39:15:37.8468 G0393771 05:05:44 17:21:28.9747 -07:09:55.9764 G0601575 05:06:55 17:21:45.4687 -00:47:43.2564 G0611033 05:08:10 17:23:05.3832 +12:41:43.512 G0686176 05:09:26 17:24:37.8295 -02:43:06.222 G0678938 05:10:35 17:27:40.6349 -06:41:02.238 G0585341 05:11:45 17:35:42.6854 -07:41:34.7424 G0707284 05:13:08 17:40:05.1636 +33:48:41.1012 G0710164 05:15:07 17:42:31.9702 +00:13:00.336 G1308107 05:16:19 17:42:50.2001 -09:43:26.5872 G0669959 05:17:43 17:45:14.4214 +38:54:57.7944 G1059666 05:19:01 17:48:43.2055 +24:39:07.3404 G0627653 05:20:19 17:50:35.0904 -01:39:06.3288 G0771881 05:21:43 17:52:41.8286 +29:50:19.3596 G0563085 05:23:01 17:55:27.9053 -00:01:52.5144 G0636803 05:24:20 17:56:20.2442 +26:21:59.58 G0638214 05:25:38 18:02:09.4776 +12:52:02.1504 G0754747 05:26:50 18:11:54.9024 +07:43:50.61 G1347890 05:27:59 18:12:50.4859 +07:30:08.928 G0794966 05:29:12 18:14:28.5058 +00:46:55.1928 G1856081 05:30:26 18:16:40.56 +15:17:56.04 G0233642 05:31:42 18:26:07.163 +03:01:37.5384 G0826631 05:32:55 18:28:01.4722 +16:07:32.7612 G0154905 05:34:20 18:52:14.1797 -23:16:18.21 G0691261 05:35:50 18:57:37.5 +38:00:32.202 G1849647 05:37:31 22:49:54.72 +11:36:29.592 G0010892 06:31:39 23:14:54.2578 -20:59:45.3408 G0706844 06:32:51 23:17:27.2242 -10:01:50.466 G0703575 06:35:09 23:18:52.5439 -10:15:33.5268 G0551567 06:36:21 23:21:14.1725 -21:14:09.8736 G0553140 06:37:30 23:22:00.9228 -23:30:24.6924 G0582772 06:38:41 23:22:35.2735 -13:05:38.8392 G0001180 06:39:51 23:24:06.9506 -11:51:38.6856 G0800782 06:41:00 23:29:56.6969 -12:29:05.7048 G0606247 06:42:09 23:30:23.7377 -12:04:45.5448 G0820960 06:43:23 23:32:31.3476 -24:00:18.5652 G0556216 06:44:32 23:37:06.9288 -20:27:47.0988 G0612966 06:45:41 23:40:45.9667 -20:30:31.5108 G0666486 06:46:55 23:41:52.6685 -08:38:53.7144 G0579080 06:48:08 23:45:31.3037 -20:58:49.8036 G0751781 06:51:36 23:48:54.7118 -16:32:28.2588 G1852091 06:52:43 23:48:56.88 -16:32:24.684 G0748482 06:53:53 23:54:20.9254 -17:18:21.0348 G0733653 06:55:02 23:56:47.7247 -16:30:34.5924 G0755443 06:56:12 23:58:40.525 -17:33:31.7124 G0755095 07:30:01 00:07:10.2658 -21:47:11.5008 G0559232 07:31:14 00:11:12.5945 -33:34:42.8016 G0555127 07:32:26 00:13:02.9052 -24:12:52.5024 G0587522 07:33:35 00:19:04.9488 -22:56:11.184 G0665013 07:34:47 00:19:09.3768 -24:31:23.2068 G0552516 07:35:57 00:22:38.9513 -24:07:36.9624 G0823492 07:37:08 00:31:49.3798 -26:43:13.926 G0740509 07:38:17 00:36:27.3996 -27:47:07.4472 G0708432 07:39:31 00:53:54.0602 -31:05:43.8432 G1641290 07:40:42 01:04:30.36 -33:39:15.768 G0762311 07:41:54 01:06:12.2227 -30:10:41.1744 G1641121 07:43:07 01:19:41.448 -33:06:29.556 G0783834 07:44:21 01:19:47.6698 -33:04:59.9808 G0595298 07:45:32 01:23:14.8567 -32:50:28.6008 G0629787 07:55:55 00:08:34.535 -33:51:29.9196 G0725300 07:57:04 00:09:35.5241 -32:16:36.5412 G0681282 07:58:16 00:14:33.5014 -24:42:09.7452 G0820749 07:59:25 00:20:42.0396 -23:16:58.2348 G0594514 08:00:36 00:44:15.959 -28:37:56.2728 G0589660 08:01:46 00:49:42.0413 -30:17:43.1736 G0601466 08:02:55 00:50:19.1225 -30:29:07.7928 G0697151 08:04:08 01:07:21.6086 -33:22:33.3912 G0671624 08:05:20 01:07:35.9945 -33:38:16.404 G0785220 08:06:31 01:12:09.409 -32:14:32.6148 G0783779 08:07:43 01:13:07.4479 -34:00:55.4544 G0657724 08:08:56 01:22:32.7113 -29:58:57.054 G0562220 08:11:21 01:38:28.5005 -33:36:28.9836 G0238284 08:12:35 01:38:59.6544 -28:34:20.478 G0791379 08:13:48 01:50:14.1576 -28:52:18.912 G0557460 08:15:00 01:50:41.5296 -32:36:15.102 G0749262 08:56:11 03:39:42.2206 -14:34:07.4136 G0771722 08:57:23 03:42:03.3526 -17:31:15.7764 GladeID UT(Sep03) RA_J2000 Dec_J2000 ----------------------------------------------- G0010892 08:25:01 23:14:54.2578 -20:59:45.3408 G0706844 08:26:12 23:17:27.2242 -10:01:50.466 G0713107 08:27:23 23:18:46.3769 -10:23:57.5232 G0703575 08:28:32 23:18:52.5439 -10:15:33.5268 G0551567 08:29:43 23:21:14.1725 -21:14:09.8736 G0553140 08:30:53 23:22:00.9228 -23:30:24.6924 G0582772 08:32:04 23:22:35.2735 -13:05:38.8392 G0001180 08:33:13 23:24:06.9506 -11:51:38.6856 G0800782 08:34:22 23:29:56.6969 -12:29:05.7048 G0606247 08:35:32 23:30:23.7377 -12:04:45.5448 G0820960 08:36:45 23:32:31.3476 -24:00:18.5652 G0556216 08:37:55 23:37:06.9288 -20:27:47.0988 G0612966 08:39:04 23:40:45.9667 -20:30:31.5108 G0666486 08:40:18 23:41:52.6685 -08:38:53.7144 G0579080 08:41:32 23:45:31.3037 -20:58:49.8036 G0584703 08:42:41 23:46:03.6036 -17:18:24.4296 G0682292 08:43:50 23:47:16.6992 -15:18:23.0148 G0751781 08:45:00 23:48:54.7118 -16:32:28.2588 G1852091 08:46:09 23:48:56.88 -16:32:24.684 G0748482 08:47:18 23:54:20.9254 -17:18:21.0348 G0733653 08:48:28 23:56:47.7247 -16:30:34.5924 G0755443 08:49:37 23:58:40.525 -17:33:31.7124 G0755095 09:30:03 00:07:10.2658 -21:47:11.5008 G0559232 09:31:16 00:11:12.5945 -33:34:42.8016 G0555127 09:32:27 00:13:02.9052 -24:12:52.5024 G0587522 09:33:37 00:19:04.9488 -22:56:11.184 G0665013 09:34:48 00:19:09.3768 -24:31:23.2068 G0552516 09:35:57 00:22:38.9513 -24:07:36.9624 G0823492 09:37:09 00:31:49.3798 -26:43:13.926 G0740509 09:38:18 00:36:27.3996 -27:47:07.4472 G0708432 09:39:27 00:53:54.0602 -31:05:43.8432 G1641290 09:40:41 01:04:30.36 -33:39:15.768 G0762311 09:41:50 01:06:12.2227 -30:10:41.1744 G1641121 09:43:01 01:19:41.448 -33:06:29.556 G0783834 09:44:11 01:19:47.6698 -33:04:59.9808 G0595298 09:45:23 01:23:14.8567 -32:50:28.6008 G0607401 09:46:32 01:24:34.5158 -33:10:24.6432 G0779486 09:47:42 01:24:50.3083 -31:45:23.8392 G0033739 09:48:57 01:47:44.4682 -33:36:05.5152 G0650576 09:50:11 02:15:38.0998 -33:00:31.5036 G0581927 09:51:23 02:17:13.6258 -33:00:41.5152 G1155066 09:52:36 02:35:13.4573 -29:36:16.6932 G0645820 09:53:46 02:38:45.1502 -30:48:23.3496 G0744351 09:54:55 02:44:15.8779 -31:56:31.3692 G0744589 09:56:06 02:46:41.6803 -25:20:47.8284 G0599710 09:57:18 02:56:13.0517 -28:02:31.5276 G0673848 09:58:27 02:56:42.421 -27:36:44.3808 G0607507 09:59:40 03:12:05.2524 -27:06:14.5728 G0605059 10:00:50 03:12:11.1941 -23:37:44.9004 G0803398 10:01:59 03:12:18.3096 -24:37:13.5336 G0767303 10:03:08 03:14:40.4534 -28:55:56.406 G0675048 10:04:20 03:16:22.8038 -23:48:36.7596 G0650576 10:34:49 02:15:38.0998 -33:00:31.5036 G0581927 10:35:56 02:17:13.6258 -33:00:41.5152 G0810505 10:37:10 02:25:46.3166 -26:06:50.7168 G1645381 10:38:19 02:28:16.464 -26:07:58.116 G0621255 10:39:28 02:35:21.6732 -25:31:39.7164 G0729094 10:40:37 02:37:35.3695 -26:22:04.1196 G0645820 10:41:47 02:38:45.1502 -30:48:23.3496 G0744351 10:42:56 02:44:15.8779 -31:56:31.3692 G0744589 10:44:05 02:46:41.6803 -25:20:47.8284 G0599710 10:45:17 02:56:13.0517 -28:02:31.5276 G0673848 10:46:26 02:56:42.421 -27:36:44.3808 G0625893 10:47:40 03:00:18.1229 -23:18:22.3344 G0805372 10:48:49 03:03:07.1767 -22:12:19.8108 G0691149 10:49:58 03:05:38.9611 -24:41:51.7488 G0607507 10:51:08 03:12:05.2524 -27:06:14.5728 G0605059 10:52:18 03:12:11.1941 -23:37:44.9004 G0803398 10:53:27 03:12:18.3096 -24:37:13.5336 G0642006 10:54:36 03:13:23.5886 -24:52:15.6216 G0675048 10:55:48 03:16:22.8038 -23:48:36.7596 G0699701 10:56:59 03:18:03.3581 -29:37:59.34 G0821941 10:58:08 03:20:51.7558 -30:47:19.1436 G0708674 10:59:18 03:23:17.8536 -27:39:21.1392 G0552792 11:00:29 03:25:27.6353 -22:29:25.9224 G0738507 11:01:38 03:25:44.6146 -26:23:17.1924 G0271141 11:02:52 03:27:20.8512 -13:44:54.3336 G0823848 11:04:03 03:28:43.7998 -19:57:07.7976 G0031069 11:05:14 03:29:55.7556 -28:46:03.9468 G0781950 11:06:26 03:30:46.6442 -20:31:26.634 G0707270 11:07:37 03:31:20.778 -26:06:09.2628 G0818993 11:08:46 03:31:24.3055 -20:10:06.4812 G0766666 11:25:41 02:26:36.2136 -23:25:01.3908 G1155066 11:26:52 02:35:13.4573 -29:36:16.6932 G0684350 11:28:02 02:37:33.9698 -27:26:30.12 G0634799 11:29:13 02:54:12.551 -33:43:07.7484 G0677246 11:30:24 03:03:53.8303 -24:33:54.4824 G0715403 11:31:33 03:08:11.7554 -22:55:22.3824 G0656204 11:32:43 03:11:09.8849 -25:19:14.4696 G0609459 11:33:52 03:11:34.5859 -26:53:47.4072 G0594595 11:35:01 03:12:26.5841 -27:08:24.594 G0675679 11:36:11 03:13:28.9006 -25:23:01.6548 G0723713 11:37:22 03:14:32.9746 -34:07:39.8316 G0767303 11:38:32 03:14:40.4534 -28:55:56.406 G0626814 11:39:41 03:16:08.7864 -29:18:20.412 G0625541 11:40:51 03:17:41.9623 -29:36:34.326 G0622813 11:42:05 03:18:03.7783 -19:29:15.0396 G0556222 11:43:16 03:19:17.3393 -27:07:40.5408 G0631899 11:44:26 03:20:03.3161 -27:00:56.2644 G0777203 11:45:35 03:22:07.9514 -27:34:54.5016 G0638952 11:46:49 03:24:05.4098 -16:18:36.864 G0675283 11:48:02 03:24:36.7548 -32:34:11.6292 G0626600 11:49:13 03:25:23.2042 -25:40:44.238 G0622938 11:50:25 03:26:14.7134 -21:01:52.3416 G0819935 11:51:36 03:27:41.0486 -28:23:19.8924 G0780661 11:52:47 03:28:47.6285 -23:23:25.5984 G0796339 11:53:59 03:29:21.1781 -28:08:00.0888 G0761570 11:55:08 03:30:14.8618 -24:21:31.9788 G0755903 11:56:18 03:30:17.7154 -24:21:08.9748 G0789550 11:57:29 03:32:49.2838 -32:40:07.4352 G0600093 11:58:42 03:33:48.695 -19:33:39.9996 G0563134 11:59:55 03:33:56.6153 -32:39:38.772 G0731177 12:22:07 03:31:31.3651 -27:28:47.0424 G0779774 12:23:18 03:32:31.4455 -22:23:43.6848 G0575234 12:24:28 03:34:42.1178 -20:50:50.2224 G0611152 12:25:38 03:37:31.627 -24:50:36.5928 G0627186 12:26:47 03:38:46.4126 -24:59:57.5088 G0277857 12:27:59 03:39:11.1814 -33:31:58.008 G0749262 12:29:14 03:39:42.2206 -14:34:07.4136 G0549570 12:30:23 03:42:03.0845 -18:29:00.9492 G0638801 12:31:33 03:42:17.6551 -22:44:51.9936 G0560055 12:32:43 03:43:20.5416 -18:28:37.974 G0664307 12:33:54 03:44:58.3282 -26:41:14.6832 G0712331 12:35:06 03:45:37.3142 -21:54:55.224 G0684551 12:36:15 03:47:07.5221 -24:31:50.304 G0705953 12:37:24 03:48:24.613 -21:25:53.2056 G0765196 12:38:34 03:49:00.8863 -22:14:25.908 G0629465 12:39:47 03:50:59.7655 -08:56:53.6352 G0772925 12:40:58 03:56:04.2718 -18:01:15.0636 G0771674 12:42:10 03:56:47.3474 -27:20:50.2512 G0665089 12:43:21 03:57:38.0897 -19:12:59.796 G0822929 12:44:30 03:57:46.9171 -26:13:29.8164 G0802406 12:45:40 03:58:51.2522 -27:47:49.6896 G0808004 12:46:49 03:59:06.2256 -27:20:33.9576 G0639673 12:47:58 03:59:20.5627 -24:19:26.022 G0734222 12:49:07 03:59:48.8268 -25:15:24.2388 G0729018 12:50:18 03:59:55.307 -24:57:49.2336 G0797844 12:51:27 03:59:55.8828 -24:29:20.238 G0605409 12:52:36 04:01:19.6171 -27:42:28.5732 G0822427 12:53:50 04:02:34.769 -22:18:22.4172 G0129198 12:55:03 04:08:07.4285 -08:49:45.3324 G0628998 12:56:18 04:09:06.1579 +15:30:50.0328 G0659256 13:03:23 03:38:40.5679 +09:58:11.9388 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25665 SUBJECT: LIGO/Virgo S190901ap: NOT spectroscopy of AT2019pjv DATE: 19/09/05 10:25:51 GMT FROM: Erkki Kankare at University of Turku E. Kankare (U. Turku), P. Lundqvist (Stockholm U.), R. Kotak, S. Mattila (U. Turku), M. A. P. Torres (IAC/ULL/SRON), T. Heikkilä, H. Kuncarayakti, T. Reynolds (U. Turku), S. Moran (NOT), D. Steeghs, J. Lyman (U. Warwick), T. Pursimo, J. Martikainen (NOT), report on behalf of a larger GOTO and NOT collaboration: We obtained a spectrum of AT2019pjv discovered by MASTER (Lipunov et al., GCN #25649) that was also observed by GOTO (Ackley et al., GCN #25654) and HMT (Yu et al., GCN #25659) within the sky localization region of the LIGO/Virgo event S190901ap (LVC et al., GCN #25606, GCN #25614). The 1200 sec observation was obtained at the 2.56 m Nordic Optical Telescope equipped with ALFOSC, and started at 2019-09-04T20:42:48 (range 350-960 nm; resolution 1.6 nm). Reasonable matches are obtained using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) and template set 2.0 with SN 1991T-like type Ia SNe 2005eq, 1998es, 1999aa roughly 8 days before maximum at z = 0.013 +/- 0.007. Our classification confirms that previously reported by Nascimbeni et al. (GCN #25661). However, our redshift estimate is somewhat lower than that reported by Nascimbeni et al., but as we do not detect any narrow lines that could be from a putative host galaxy, we cannot fully exclude the possibility that AT2019pjv is not directly associated with MCG +05-41-001 at z = 0.023 (SDSS, DR12). This obviously has no effect on the main conclusion of Nascimbeni et al. that AT2019pjv is unrelated to S190901ap. Based on observations taken with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The data presented here were obtained with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25666 SUBJECT: LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA DATE: 19/09/05 11:42:43 GMT FROM: Kateryna Barynova at Kiev Uni., GRANDMA K. Barynova (CEA-Irfu/Univ Kiev), W. Lin (THU), D. Corre (LAL), S. Antier (APC), M. Boer (Artemis), N. Christensen (Artemis), L. Eymar (Artemis), A. Klotz (IRAP), K. Noysen (Artemis, IRAP), S. Basa (LAM), J.G. Ducoin (LAL), M. Coughlin (Caltech), D. Coward (OzGrav-UWA), P. Hello (LAL), N. Leroy (LAL), D. Turpin (NAOC), C. Thone (HETH/IAA-CSIC), X. Wang (THU) Report on behalf of the TAROT network and GRANDMA collaborations. We performed tiled observations of the LIGO/Virgo event S190901ap event (GCN #25606) with the TAROT-Chile (TCH), TAROT-Calern (TCA) and TAROT-Reunion (TRE) telescopes operating in the visible located respectively at La Silla ESO observatory (LaS/ESO), the Calern site at the Cote d'Azur observatory and at La Reunion Island, France. The observation started for TRE at 09/01/19 23:57:14 UTC which corresponds approximately to 27 minutes after the GW trigger time, for TCA at 09/02/19 00:45:34 UTC which corresponds approximately to 75 minutes after the GW trigger time, and for TCH at 09/02/19 03:59:57 UTC which corresponds approximately to 269 minutes after the GW trigger time. We performed the following tiled observations : +-------+------------+------------+---------+---------+---------+ | Tele | TStart | TEnd | RA | DEC | Proba | | scope | [UTC] | [UTC] | [deg] | [deg] | [%] | |-------+------------+------------+---------+---------+---------| | TRE | 2019-09-01 | 2019-09-02 | 56.1 | -22.445 | 0.5 | | | 23:57:14 | 19:55:53 | | | | | TRE | 2019-09-02 | 2019-09-02 | 63.563 | -18.355 | 0.5 | | | 00:10:23 | 21:08:16 | | | | | TRE | 2019-09-02 | 2019-09-02 | 59.173 | -18.355 | 0.5 | | | 21:40:00 | 21:46:28 | | | | | TRE | 2019-09-02 | 2019-09-04 | 48.853 | -26.536 | 0.5 | | | 21:52:55 | 01:39:05 | | | | | TRE | 2019-09-02 | 2019-09-03 | 60.705 | -10.173 | 0.5 | | | 22:11:52 | 21:42:47 | | | | | TRE | 2019-09-02 | 2019-09-03 | 62.1 | -14.264 | 0.4 | | | 22:24:38 | 00:38:54 | | | | | TRE | 2019-09-02 | 2019-09-04 | 67.954 | -18.355 | 0.5 | | | 22:56:19 | 00:35:23 | | | | | TRE | 2019-09-02 | 2019-09-02 | 57.814 | -14.264 | 0.5 | | | 23:21:47 | 23:28:20 | | | | | TRE | 2019-09-02 | 2019-09-03 | 65.1 | -22.445 | 0.5 | | | 23:35:00 | 20:58:07 | | | | | TRE | 2019-09-03 | 2019-09-03 | 50.749 | -30.627 | 0.4 | | | 00:51:12 | 22:14:50 | | | | | TRE | 2019-09-03 | 2019-09-03 | 44.178 | -26.536 | 0.4 | | | 19:21:53 | 19:28:21 | | | | | TRE | 2019-09-03 | 2019-09-03 | 55.614 | -30.627 | 0.4 | | | 21:55:02 | 22:01:30 | | | | | TRE | 2019-09-03 | 2019-09-03 | 70.671 | -14.264 | 0.5 | | | 22:39:59 | 22:46:27 | | | | | TRE | 2019-09-03 | 2019-09-03 | 51.6 | -22.445 | 0.5 | | | 22:53:01 | 22:59:35 | | | | | TRE | 2019-09-03 | 2019-09-03 | 66.386 | -14.264 | 0.5 | | | 23:05:36 | 23:12:04 | | | | | TRE | 2019-09-03 | 2019-09-03 | 60.6 | -22.445 | 0.5 | | | 23:18:31 | 23:24:59 | | | | |-------+------------+------------+---------+---------+---------| | TCA | 2019-09-02 | 2019-09-04 | 59.998 | -12.967 | 0.1 | | | 00:45:34 | 01:00:07 | | | | | TCA | 2019-09-02 | 2019-09-04 | 61.264 | -11.112 | 0.1 | | | 00:52:23 | 01:51:39 | | | | | TCA | 2019-09-02 | 2019-09-02 | 57.214 | -18.535 | 0.1 | | | 00:59:12 | 01:05:42 | | | | | TCA | 2019-09-02 | 2019-09-02 | 66.919 | -11.112 | 0.1 | | | 01:11:30 | 03:28:20 | | | | | TCA | 2019-09-02 | 2019-09-04 | 60.629 | -14.823 | 0.1 | | | 01:18:19 | 02:39:22 | | | | | TCA | 2019-09-02 | 2019-09-03 | 63.75 | -9.256 | 0.1 | | | 01:25:08 | 02:45:10 | | | | | TCA | 2019-09-02 | 2019-09-03 | 58.093 | -12.967 | 0.1 | | | 01:37:24 | 03:36:21 | | | | | TCA | 2019-09-02 | 2019-09-02 | 69.375 | -9.256 | 0.1 | | | 01:44:14 | 04:00:59 | | | | | TCA | 2019-09-02 | 2019-09-04 | 60.95 | -9.256 | 0.1 | | | 01:53:18 | 01:39:22 | | | | | TCA | 2019-09-02 | 2019-09-04 | 52.663 | -20.39 | 0.1 | | | 02:16:56 | 02:05:19 | | | | | TCA | 2019-09-02 | 2019-09-02 | 61.902 | -12.967 | 0.1 | | | 02:23:45 | 02:30:15 | | | | | TCA | 2019-09-02 | 2019-09-02 | 64.084 | -11.112 | 0.1 | | | 02:35:44 | 02:42:14 | | | | | TCA | 2019-09-02 | 2019-09-02 | 59.646 | -18.535 | 0.1 | | | 02:42:33 | 02:49:03 | | | | | TCA | 2019-09-02 | 2019-09-02 | 61.602 | -18.535 | 0.1 | | | 02:49:22 | 02:55:53 | | | | | TCA | 2019-09-02 | 2019-09-02 | 72.2 | -9.256 | 0.1 | | | 03:15:01 | 03:17:01 | | | | | TCA | 2019-09-02 | 2019-09-02 | 66.575 | -9.256 | 0.1 | | | 03:40:50 | 03:47:21 | | | | | TCA | 2019-09-03 | 2019-09-03 | 55.713 | -12.967 | 0.1 | | | 00:21:30 | 02:38:21 | | | | | TCA | 2019-09-03 | 2019-09-03 | 63.807 | -12.967 | 0.1 | | | 00:54:03 | 01:00:33 | | | | | TCA | 2019-09-03 | 2019-09-04 | 50.674 | -20.39 | 0.1 | | | 01:00:52 | 00:53:16 | | | | | TCA | 2019-09-03 | 2019-09-03 | 69.521 | -12.967 | 0.1 | | | 01:26:26 | 03:43:11 | | | | | TCA | 2019-09-03 | 2019-09-04 | 57.079 | -16.679 | 0.1 | | | 01:33:16 | 01:25:40 | | | | | TCA | 2019-09-03 | 2019-09-04 | 54.652 | -20.39 | 0.1 | | | 01:40:05 | 01:32:31 | | | | | TCA | 2019-09-03 | 2019-09-03 | 67.617 | -12.967 | 0.1 | | | 01:52:16 | 04:08:27 | | | | | TCA | 2019-09-03 | 2019-09-04 | 56.779 | -14.823 | 0.1 | | | 02:05:54 | 01:58:29 | | | | | TCA | 2019-09-03 | 2019-09-03 | 55.789 | -18.535 | 0.1 | | | 02:18:13 | 02:24:43 | | | | | TCA | 2019-09-03 | 2019-09-03 | 57.495 | -11.112 | 0.1 | | | 02:25:02 | 02:31:32 | | | | | TCA | 2019-09-03 | 2019-09-03 | 70.213 | -11.112 | 0.1 | | | 03:23:02 | 03:29:32 | | | | | TCA | 2019-09-04 | 2019-09-04 | 53.208 | -16.679 | 0.1 | | | 02:30:32 | 02:37:03 | | | | |-------+------------+------------+---------+---------+---------| | TCH | 2019-09-02 | 2019-09-04 | 57.079 | -19.959 | 0.1 | | | 03:59:57 | 07:02:59 | | | | | TCH | 2019-09-02 | 2019-09-02 | 55.363 | -25.414 | 0.1 | | | 04:06:45 | 08:46:05 | | | | | TCH | 2019-09-02 | 2019-09-02 | 61.285 | -25.414 | 0.1 | | | 04:13:33 | 04:20:03 | | | | | TCH | 2019-09-02 | 2019-09-02 | 51.238 | -25.495 | 0.1 | | | 04:20:21 | 06:35:40 | | | | | TCH | 2019-09-02 | 2019-09-04 | 68.686 | -16.323 | 0.1 | | | 04:51:50 | 09:38:48 | | | | | TCH | 2019-09-02 | 2019-09-02 | 43.554 | -30.868 | 0.1 | | | 04:58:39 | 09:58:11 | | | | | TCH | 2019-09-02 | 2019-09-02 | 54.652 | -23.595 | 0.1 | | | 05:05:27 | 07:34:48 | | | | | TCH | 2019-09-02 | 2019-09-02 | 62.35 | -14.505 | 0.1 | | | 05:24:17 | 05:30:47 | | | | | TCH | 2019-09-02 | 2019-09-02 | 59.998 | -18.141 | 0.1 | | | 05:31:05 | 08:00:06 | | | | | TCH | 2019-09-02 | 2019-09-02 | 57.214 | -21.777 | 0.1 | | | 05:37:53 | 05:44:23 | | | | | TCH | 2019-09-02 | 2019-09-02 | 60.95 | -19.959 | 0.1 | | | 05:56:40 | 06:03:10 | | | | | TCH | 2019-09-02 | 2019-09-02 | 58.093 | -18.141 | 0.1 | | | 06:03:28 | 06:09:58 | | | | | TCH | 2019-09-02 | 2019-09-02 | 53.352 | -25.414 | 0.1 | | | 06:35:58 | 06:42:28 | | | | | TCH | 2019-09-02 | 2019-09-02 | 56.641 | -23.595 | 0.1 | | | 06:42:46 | 06:49:16 | | | | | TCH | 2019-09-02 | 2019-09-02 | 59.014 | -19.959 | 0.1 | | | 09:38:11 | 09:44:41 | | | | | TCH | 2019-09-02 | 2019-09-02 | 45.684 | -30.868 | 0.1 | | | 10:10:53 | 10:15:08 | | | | | TCH | 2019-09-03 | 2019-09-04 | 65.572 | -21.777 | 0.1 | | | 04:34:32 | 08:46:48 | | | | | TCH | 2019-09-03 | 2019-09-03 | 55.691 | -23.595 | 0.1 | | | 05:06:45 | 09:32:17 | | | | | TCH | 2019-09-03 | 2019-09-04 | 53.742 | -32.686 | 0.1 | | | 05:13:33 | 09:25:11 | | | | | TCH | 2019-09-03 | 2019-09-03 | 55.422 | -16.323 | 0.1 | | | 05:32:44 | 07:49:08 | | | | | TCH | 2019-09-03 | 2019-09-04 | 57.787 | -16.323 | 0.1 | | | 05:39:32 | 07:41:53 | | | | | TCH | 2019-09-03 | 2019-09-04 | 67.617 | -18.141 | 0.1 | | | 05:51:49 | 10:04:18 | | | | | TCH | 2019-09-03 | 2019-09-04 | 57.2 | -14.505 | 0.1 | | | 05:58:37 | 10:11:06 | | | | | TCH | 2019-09-03 | 2019-09-03 | 60.632 | -16.323 | 0.1 | | | 06:05:25 | 08:20:57 | | | | | TCH | 2019-09-03 | 2019-09-04 | 64.821 | -19.959 | 0.1 | | | 06:24:24 | 06:17:37 | | | | | TCH | 2019-09-03 | 2019-09-04 | 52.826 | -21.777 | 0.1 | | | 06:31:13 | 08:33:12 | | | | | TCH | 2019-09-03 | 2019-09-04 | 55.144 | -20.909 | 0.1 | | | 06:38:01 | 08:40:00 | | | | | TCH | 2019-09-03 | 2019-09-04 | 53.208 | -19.959 | 0.1 | | | 06:56:39 | 04:39:47 | | | | | TCH | 2019-09-03 | 2019-09-04 | 52.108 | -17.273 | 0.1 | | | 07:03:27 | 06:56:11 | | | | | TCH | 2019-09-03 | 2019-09-04 | 51.238 | -25.495 | 0.1 | | | 07:29:02 | 09:31:59 | | | | | TCH | 2019-09-03 | 2019-09-04 | 54.283 | -18.141 | 0.1 | | | 08:27:57 | 08:21:00 | | | | | TCH | 2019-09-03 | 2019-09-03 | 56.188 | -18.141 | 0.1 | | | 09:00:05 | 09:06:35 | | | | | TCH | 2019-09-03 | 2019-09-04 | 68.45 | -14.505 | 0.1 | | | 10:05:03 | 09:57:30 | | | | | TCH | 2019-09-04 | 2019-09-04 | 62.608 | -23.595 | 0.1 | | | 05:57:31 | 06:04:01 | | | | +-------+------------+------------+---------+---------+---------+ TStart and TEnd refer respectively to the time of the first and last exposure for a given tile. Observations are not necessarily continuous in this interval. The "Probability" column refers to the 2D spatial probability of the GW skymap enclosed in a given tile. Each tile is 1.9x1.9 degrees for both TCA and TCH and 4.2x4.2 degrees for TRE. The coordinating observations cover about 9% of the cumulative probability of the LALInference skymap available on Sep 2, 2019 11:21:57 UTC. The typical limiting magnitude in AB mode is 18.0 for a 60.0 s exposure for TCH and TCA and 17.0 for a 60.0 s exposure for TRE. The coverage map is available at: https://grandma-owncloud.lal.in2p3.fr/index.php/s/GDhyzNjw9xGJALH No significant transient candidates were found during our low latency analysis. 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 (https://grandma.lal.in2p3.fr/). Details on the TAROT telescopes are available on the GRANDMA web pages. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25674 SUBJECT: LIGO/Virgo S190901ap: Second Epoch Hobby-Eberly Telescope observations of ZTF19abvionh DATE: 19/09/06 02:32:45 GMT FROM: J. Craig Wheeler at U.Texas Austin M. J. B. Rosell, Greg Zeimann, Karl Gebhardt, Aaron Zimmerman, Matthew Shetrone, Chris Fryer, J. Craig Wheeler, Steve Odewahn, and Nathan McReynolds on behalf of the LIGO Hobby-Eberly Telescope Response (LIGHETR) team,report a second epoch of spectroscopic observations of the optical transient ZTF19abvionh(Kool et al. GCN #25616, Rosell et al. GCN #25620, Kumar et al. GCN 25632, Burdge et al. GCN #25638) on 9/03/19. Observations were made with the VIRUS IFU spectrograph that covers the wavelength range of 3500 to 5500 Angstroms and with the blue and orange arms of the LRS2 spectrograph that cover the range 3400 to 7000 Angstroms. We confirm the emission lines at 4124 Angstroms and 5370 Angstroms that correspond to [O II] 3727 and Hbeta at a redshift of ~0.1 associated with S0 galaxy GALEXASC J165500.03+140301.3. We detect very little change in the amplitude or spectrum compared with the first epoch of observations. The flux at 5700 Angstroms is roughly consistent with the photometry reported by Kumar et al. The optical candidate shows a blue continuum corresponding to a BB temperature of about 10,500K. The VIRUS and LRS2 spectra are consistent in the overlap region. Both sets of data show a somewhat broadened (~25 Angstroms FWHM) emission feature at ~4686 Angstroms. The LRS2 data also show a somewhat smaller emission feature at ~6563 Angstroms with roughly the same width. We tentatively identify the former as He II perhaps blended with N III and the latter with Halpha, both with negligible redshift. The line broadening suggests a velocity of ~1700 km/s. The optical candidate does not have the properties expected of a merger event and hence is unrelated to S190901ap. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25675 SUBJECT: LIGO/Virgo S190901ap: ZTF19abwvals is a type-Ia SN near maximum DATE: 19/09/06 12:41:49 GMT FROM: Daniele B Malesani at DTU Space L. Izzo (DARK/NBI), G. Leloudas (DTU Space), S. H. Bruun (DARK/NBI), K. E. Heintz (Univ. Iceland), B. Milvang-Jensen (DAWN/NBI), J. Hjorth (DARK/NBI), J. P. U. Fynbo (DAWN/NBI), D. B. Malesani (DTU Space), S. Piranomonte (INAF/OARm), T. Pursimo (NOT), J. Martikainen (NOT and Univ. Helsinki), report on behalf of a larger collaboration: We observed the transient ZTF19abwvals (Stein et al., GCN 25656) discovered by the Zwicky Transient Facility as a candidate counterpart of the LIGO/Virgo GW event S190901ap (LIGO Scientific Collaboration and Virgo Collaboration, GCNs 25606, 25614), using the Nordic Optical Telescope equipped with the ALFOSC spectrograph. A spectrum by 2x1200 s was acquired covering the wavelength range 3200-9600 AA, starting on 2019 September 5.20 UT. In the acquisition image (taken without filter) the transient is detected, approximately 0.9" to the NW of the galaxy nucleus and hence blended with it given the seeing of approximately 1". In the spectral extraction, a sizable contribution from the host galaxy is present. Template-matching using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) and DASH (https://astrodash.readthedocs.io) shows that ZTF19abwvals is a normal type-Ia SN at a phase of 4-6 days after maximum, at a redshift z = 0.091 +- 0.004. The redshift is consistent with the SDSS photometric value z_ph = 0.13 +- 0.03 of the host galaxy. Considering the foreground Galactic extinction (A_r = 1.04 mag) and the measurement by Stein et al. (GCN 25656), the absolute magnitude of the transient at z = 0.091 is M_r ~ -19.4, consistent with a type-Ia SN near peak. The above classification excludes ZTF19abwvals as a counterpart of S190901ap. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25688 SUBJECT: LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations DATE: 19/09/09 13:53:09 GMT FROM: Jean-Gregoire Ducoin at LAL J.G. Ducoin (LAL), S. Antier (APC), B. Chabert (IRAP), D. Corre (LAL), A. Klotz (IRAP), D. Turpin (NAOC), S. Basa (LAM), M. Boer (Artemis), N. Christensen (Artemis), A. Coleiro (APC), M. Coughlin (Caltech), D. Coward (OzGrav-UWA), P. Hello (LAL), N. Leroy (LAL), C. Thone (HETH/IAA-CSIC), X. Wang (THU) Report on behalf of the GRANDMA collaboration. We performed galaxy-targeted observations of the LIGO/Virgo event S190901ap event (GCN #25606) with the amator astronomers of GRANDMA citizen science program "kilonova-catcher" created by CNRS/IRAP and CNRS/LAL. Denis St-Gelais, Raymond Kneip and Peter Jaquiery performed galaxy-targeted observations in clear filter of the S190901ap event. Denis St-Gelais imaged 8 fields with a 36-cm telescope located in Querétaro (Mexico): the typical limiting magnitude is 19 for a 60.0 s exposure. Peter Jaquiery imaged 8 fields with a 35-cm telescope at Berverly-Begg Observatory (New Zealand): the typical magnitude is 18.5 for an exposure time of 10 min. Raymond Kneip imaged four fields with K26 35-cm telescope at Contern observatory (Luxembourg): the typical limiting magnitude is 18.5 mag for 20 min exposure. The target galaxies are selected from the list of potential host galaxies from the GLADE catalog in the 90% credible area of the localization region of the LIGO/Virgo GW event. Note that these galaxies are compatible within 3 sigma with the distance of the GW event. No significant transient candidates were found during our analysis. The coverage map is available at: https://grandma-owncloud.lal.in2p3.fr/index.php/s/GDhyzNjw9xGJALH The list of the galaxies we observed is given in the tables below. TStart and TEnd refers respectively to the time of the first and last exposure for a given galaxy. Observations are not necessarily continuous in this interval. +----------+----------+-----------------------+--------+--------+------+ |TStart | TEnd | Galaxy | RA | DEC | Dist.| |[UTC] | [UTC] | name | [deg] | [deg] | [Mpc]| |----------+----------+-----------------------+--------+--------+------| |2019-09-02|2019-09-02|HyperLEDA 58263 |247.161 |39.0833 |142.86| | 20:45:30 | 20:57:30 | | | | | |2019-09-03|2019-09-03|2MASS 03582008-0532062 |59.5837 |-5.5351 |280.33| | 04:10:12 | 04:36:04 | | | | | |2019-09-03|2019-09-03|2MASS 17054435+2214502 |256.4348|22.2473 |213.86| | 04:42:08 | 05:09:20 | | | | | |2019-09-03|2019-09-03|HyperLEDA HIZOAJ1825-07|276.488 |-7.1932 |162.92| | 05:21:17 | 05:50:26 | | | | | |2019-09-03|2019-09-03|HyperLEDA HIZOAJ1814-08|273.762 |-8.6037 |160.01| | 05:55:27 | 06:04:02 | | | | | |2019-09-03|2019-09-03|2MASS 02262568-2820588 |36.6070 |-28.3497|311.49| | 07:23:29 | 07:50:49 | | | | | |2019-09-03|2019-09-03|2MASS 02351345-2936166 |38.80607|-29.6046|267.85| | 08:06:32 | 08:42:21 | | | | | |2019-09-03|2019-09-03|2MASS 03111883-2046184 |47.82849|-20.7718|305.52| | 09:03:31 | 09:30:46 | | | | | |2019-09-03|2019-09-03|2MASS 03415732-1106138 |55.48884|-11.1039|246.10| | 09:36:01 | 10:34:18 | | | | | |2019-09-03|2019-09-03|2MASS 23263752-6106015 |351.6563|-61.1004|177.63| | 09:44:34 | 10:04:34 | | | | | |2019-09-03|2019-09-03|HyperLEDA HIZOAJ1825-07|276.488 |-7.19323|162.92| | 10:21:07 | 10:41:07 | | | | | |2019-09-03|2019-09-03|HyperLEDA HIZOAJ1814-08|273.762 |-8.60367|160.01| | 11:15:29 | 11:35:29 | | | | | |2019-09-03|2019-09-03|HyperLEDA ESO410-024 |9.11416 |-27.7854|149.38| | 11:28:45 | 11:37:45 | | | | | |2019-09-03|2019-09-03|HyperLEDA ESO351-016 |13.09514|-35.0007|200.54| | 12:21:09 | 12:31:09 | | | | | |2019-09-03|2019-09-03|HyperLEDA ESO411-028 |13.47525|-31.0955|137.69| | 12:38:20 | 12:48:20 | | | | | |2019-09-03|2019-09-03|HyperLEDA ESO352-002 |16.1265 |-33.6544|141.76| | 12:58:27 | 13:18:27 | | | | | |2019-09-03|2019-09-03|2MASS 01234572-5848208 |20.94051|-58.8058|205.94| | 13:28:49 | 13:48:49 | | | | | |2019-09-03|2019-09-03|2MASS 16350144+3054117 |248.7560|30.90327|300.65| | 19:52:00 | 20:15:00 | | | | | |2019-09-03|2019-09-03|2MASS 17111820+1650431 |257.8259|16.84531|252.86| | 20:19:00 | 20:42:00 | | | | | |2019-09-03|2019-09-03|2MASS 18350342+3241471 |278.7642|32.69643|258.88| | 20:45:00 | 21:08:00 | | | | | +----------+----------+-----------------------+--------+--------+------+ 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 (https://grandma.lal.in2p3.fr/). Details on the GRANDMA web pages and the citizen science program "kilonova-catcher" are available on https://grandma-kilonovacatcher.lal.in2p3.fr/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25689 SUBJECT: LIGO/Virgo S190901ap: Gaia Photometric Alerts transient candidates DATE: 19/09/09 14:35:53 GMT FROM: Zuzanna Kostrzewa-Rutkowska at SRON Z. Kostrzewa-Rutkowska (Leiden Observatory), S. Hodgkin, A. Delgado, D.L. Harrison, M. van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), D. Eappachen, P.G. Jonker (SRON/RU) on behalf of Gaia Alerts team report the discovery of transient candidates within the probability skymap of S190901ap (the LIGO Scientific Collaboration and the Virgo Collaboration, GCN 25606): --------------------------------------------------------------------------- Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL --------------------------------------------------------------------------- SN candidates: Gaia19dyu AT2019psg 2019-09-05T07:22:03 40.96499 -58.29228 18.95 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dyu/ Gaia19dxp AT2019pqc 2019-09-06T07:19:43 43.59650 -53.69043 18.88 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dxp/ Gaia19dxf AT2019pns 2019-09-04T19:11:27 57.21955 -55.42570 17.87 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dxf/ Gaia19dxd AT2019pnr 2019-09-05T13:24:10 37.51050 -58.24664 18.99 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dxd/ Gaia19dxc AT2019pnq 2019-09-05T12:31:35 86.95212 -25.16602 18.57 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dxc/ --------------------------------------------------------------------------- posible CV candidates: Gaia19dyy AT2019psj 2019-09-06T22:48:33 282.48546 -7.85814 18.00 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dyy/ Gaia19dym AT2019pra 2019-09-06T15:16:29 274.56785 6.03930 18.13 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dym/ Gaia19dxx AT2019pqq 2019-09-05T23:03:26 275.72895 7.81160 17.53 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dxx/ Gaia19dxt AT2019pqe 2019-09-04T21:14:57 279.59279 8.11615 18.85 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dxt/ --------------------------------------------------------------------------- Acknowledgements: This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. DE and PGJ acknowledge support from the European Research Council under ERC Consolidator Grant agreement no 647208. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25716 SUBJECT: LIGO/Virgo S190901ap: Gaia Photometric Alerts transient candidates DATE: 19/09/10 13:38:57 GMT FROM: Zuzanna Kostrzewa-Rutkowska at SRON Z. Kostrzewa-Rutkowska (Leiden Observatory), S. Hodgkin, A. Delgado, D.L. Harrison, M. van Leeuwen, G. Rixon, A. Yoldas (IoA Cambridge), D. Eappachen, P.G. Jonker (SRON/RU) on behalf of Gaia Alerts team report the discovery of transient candidates within the probability skymap of S190901ap (the LIGO Scientific Collaboration and the Virgo Collaboration, GCN 25606): --------------------------------------------------------------------------- Name TNSid Date [TCB] RaDeg DecDeg AlertMag URL --------------------------------------------------------------------------- Gaia19dzv AT2019pwe 2019-09-08T13:35:59 20.00637 -51.06273 18.85 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dzv/ Gaia19dzi AT2019piw 2019-09-07T18:33:54 79.57534 -19.22286 18.17 http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia19dzi/ Acknowledgements: This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. DE and PGJ acknowledge support from the European Research Council under ERC Consolidator Grant agreement no 647208. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25724 SUBJECT: LIGO/Virgo S190901ap: WHT spectroscopy of Gaia19dzi DATE: 19/09/11 06:10:54 GMT FROM: Giacomo Cannizzaro at SRON G. Cannizzaro (SRON/Radboud Univ), I. Pastor-Marazuela (API/ASTRON), P. Jonker (SRON/Radboud Univ) report on behalf of the GW@WHT collaboration: We obtained optical spectroscopy of Gaia19dzi (GCN 25716), an optical transient within the LIGO/Virgo S190901ap sky localisation (GCN 25606) with the ACAM instrument mounted on the William Herschel Telescope located at the Roque de Los Muchachos Observatory, La Palma, Spain. We cross-correlate the transient spectra with a library of supernova template spectra using the code SNID (Blondin and Tonry, 2007). Gaia19dzi is classified as a SNIa, with a redshift of z=0.06. [GCN OPS NOTE(11sep19): Per author's request, in the Subject-line and first sentence the "S190910ap" was changed to "S190901ap".]