//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30101 SUBJECT: GRB 210529B: Fermi GBM Final Real-time Localization DATE: 21/05/30 00:04:01 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely SHORT GRB At 23:53:37 UT on 29 May 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210529B (trigger 644025222.097546 / 210529996). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 230.0, Dec = 36.3 (J2000 degrees, equivalent to J2000 15h 20m, 36d 17'), with a statistical uncertainty of 5.8 degrees. The angle from the Fermi LAT boresight is 16.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210529996/quicklook/glg_skymap_all_bn210529996.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210529996/quicklook/glg_healpix_all_bn210529996.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210529996/quicklook/glg_lc_medres34_bn210529996.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30102 SUBJECT: Fermi GRB 210529B: Global MASTER-Net observations report DATE: 21/05/30 00:35:27 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), 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-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 210529B ( Fermi GBM team, GCN 30101) errorbox 252 sec after notice time and 280 sec after trigger time at 2021-05-29 23:58:17 UT, with upper limit up to 19.1 mag. The observations began at zenith distance = 8 deg. The sun altitude is -38.1 deg. The galactic latitude b = 57 deg., longitude l = 58 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1624282 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 310 | 2021-05-29 23:58:17 | MASTER-IAC | (15h 17m 31.41s , +35d 28m 38.8s) | C | 60 | 18.8 | 310 | 2021-05-29 23:58:17 | MASTER-IAC | (15h 07m 30.80s , +35d 34m 29.3s) | C | 60 | 18.6 | 391 | 2021-05-29 23:59:37 | MASTER-IAC | (15h 21m 01.51s , +37d 22m 04.4s) | C | 60 | 18.7 | 391 | 2021-05-29 23:59:37 | MASTER-IAC | (15h 10m 46.10s , +37d 28m 00.1s) | C | 60 | 18.4 | 471 | 2021-05-30 00:00:57 | MASTER-IAC | (15h 33m 13.00s , +33d 34m 59.5s) | C | 60 | 18.7 | 471 | 2021-05-30 00:00:57 | MASTER-IAC | (15h 23m 25.79s , +33d 40m 54.3s) | C | 60 | 18.6 | 551 | 2021-05-30 00:02:18 | MASTER-IAC | (15h 15m 03.67s , +33d 34m 18.4s) | C | 60 | 18.8 | 551 | 2021-05-30 00:02:18 | MASTER-IAC | (15h 05m 16.33s , +33d 40m 11.9s) | C | 60 | 18.8 | 661 | 2021-05-30 00:03:38 | MASTER-IAC | (15h 19m 11.04s , +36d 24m 22.1s) | P| | 120 | 18.7 | 661 | 2021-05-30 00:03:38 | MASTER-IAC | (15h 18m 01.83s , +36d 31m 04.7s) | P- | 120 | 18.4 | 816 | 2021-05-30 00:05:57 | MASTER-IAC | (15h 19m 17.02s , +36d 24m 53.4s) | P| | 150 | 18.8 | 816 | 2021-05-30 00:05:57 | MASTER-IAC | (15h 18m 08.10s , +36d 31m 35.7s) | P- | 150 | 18.5 | 1001 | 2021-05-30 00:08:47 | MASTER-IAC | (15h 19m 13.77s , +36d 26m 07.6s) | P| | 180 | 19.1 | 1001 | 2021-05-30 00:08:47 | MASTER-IAC | (15h 18m 04.84s , +36d 32m 50.5s) | P- | 180 | 18.7 | 1201 | 2021-05-30 00:12:07 | MASTER-IAC | (15h 19m 13.75s , +36d 24m 33.0s) | P| | 180 | 19.0 | 1201 | 2021-05-30 00:12:07 | MASTER-IAC | (15h 18m 04.74s , +36d 31m 16.4s) | P- | 180 | 18.7 | 1541 | 2021-05-30 00:18:48 | MASTER-IAC | (15h 17m 24.50s , +35d 28m 03.3s) | C | 60 | 18.8 | 1541 | 2021-05-30 00:18:48 | MASTER-IAC | (15h 07m 21.55s , +35d 33m 50.6s) | C | 60 | 18.6 | 1621 | 2021-05-30 00:20:08 | MASTER-IAC | (15h 21m 02.63s , +37d 23m 00.6s) | C | 60 | 18.6 | 1621 | 2021-05-30 00:20:08 | MASTER-IAC | (15h 10m 44.61s , +37d 28m 50.2s) | C | 60 | 18.4 | 1701 | 2021-05-30 00:21:28 | MASTER-IAC | (15h 33m 19.34s , +33d 33m 54.7s) | C | 60 | 18.7 | 1701 | 2021-05-30 00:21:28 | MASTER-IAC | (15h 23m 29.92s , +33d 39m 42.6s) | C | 60 | 18.6 | 1782 | 2021-05-30 00:22:48 | MASTER-IAC | (15h 14m 57.26s , +33d 33m 11.5s) | C | 60 | 18.8 | 1782 | 2021-05-30 00:22:48 | MASTER-IAC | (15h 05m 07.82s , +33d 38m 59.1s) | C | 60 | 18.8 | 1862 | 2021-05-30 00:24:08 | MASTER-IAC | (15h 25m 57.96s , +39d 15m 20.3s) | C | 60 | 18.7 | 1862 | 2021-05-30 00:24:08 | MASTER-IAC | (15h 15m 24.33s , +39d 21m 08.8s) | C | 60 | 18.5 | 1942 | 2021-05-30 00:25:29 | MASTER-IAC | (15h 36m 07.87s , +35d 28m 48.9s) | C | 60 | 18.8 | 1942 | 2021-05-30 00:25:29 | MASTER-IAC | (15h 26m 05.43s , +35d 34m 35.4s) | C | 60 | 18.5 | 2022 | 2021-05-30 00:26:49 | MASTER-IAC | (15h 40m 11.85s , +37d 20m 49.6s) | C | 60 | 18.7 | 2022 | 2021-05-30 00:26:49 | MASTER-IAC | (15h 29m 54.85s , +37d 26m 36.9s) | C | 60 | 18.5 | 2102 | 2021-05-30 00:28:09 | MASTER-IAC | (15h 06m 20.21s , +39d 17m 14.5s) | C | 60 | 18.6 | 2102 | 2021-05-30 00:28:09 | MASTER-IAC | (14h 55m 46.53s , +39d 23m 01.4s) | C | 60 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30104 SUBJECT: GRB 210529B: DDOTI Upper Limits on the Afterglow DATE: 21/05/31 02:02:56 GMT FROM: Kin O. C. L. Mendoza at Instituto de Astronoma, UNAM Océlotl Lopez (UNAM), Margarita Pereyra (UNAM), Rosa L. Becerra (UNAM), Nat Butler (ASU), Alan M. Watson (UNAM), Simone Dichiara (GSFC/UMD), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Diego Gonzalez (UNAM), Margarita Pereyra (UNAM), Srihari Ravi (ASU), and Eleonora Troja (GSFC/UMD) report: We observed the field of the Fermi GBM GRB 210529B (Fermi Collaboration, GCN Circ. 30101) with the DDOTI wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Martir ( http://ddoti.astroscu.unam.mx) from 2021-05-30 03:35 to 11:19 UTC (3.7 to 11.4 hours after the trigger). We observed a region of 20.4 degrees in RA by 20.4 degrees in declination, with a 3 x 2 grid, centered on the Fermi GBM Final Position RA: 230.01, DEC: +36.34 (J2000 degrees). This region contains 6 instrumental fields or about 400 square degrees. We obtained 58 minutes of exposure per instrumental field in the w filter. We obtained AB photometry by calibration against the APASS catalog. We detect no likely candidates for the afterglow to our 10-sigma upper limits of w = 20.25-20.58 (inter-quartile). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Martir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30109 SUBJECT: GRB210529B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 644025222) DATE: 21/06/01 10:04:08 GMT FROM: Tomas Ahumada at U. of Maryland Tomas Ahumada (UMD), Shreya Anand (Caltech), Harsh Kumar (IIT-B), Igor Andreoni (Caltech), Albert Kong (NTHU), Erik Kool (SU), Ana Sagues-Carracedo (SU), Simeon Reusch (DESY), , Michael Coughlin (UMN), Mansi Kasliwal (Caltech), Robert Stein (DESY), Leo Singer (NASA/GSFC), and Matthew Graham (Caltech) report on behalf of the ZTF collaboration: We observed the localization region of the short GRB210529B (trigger 644025222.097546) detected by the Gamma-Ray Burst Monitor (GBM) on the Fermi satellite with the Palomar 48 inch telescope equipped with the 47 square degree Zwicky Transient Facility (ZTF; Bellm et al., 2019; Graham et al., 2019) camera. We obtained a series of g- and r-band images covering about 686 square degrees beginning at 05:06:36.18 UT on 2021-05-30 (~ 5.1 hours after the burst trigger time). This corresponds to ~85% of the probability enclosed in the region of the GRB localization that was unocculted by the Earth for Fermi GBM (GCN 30101). Exposures reached a median depth of 22.2 mag in the g-band and 22.3 mag in the r-band. On 2021-05-31, we obtained another epoch of g- and r-band follow-up observations, beginning at 05:07:50.96 UT with exposures reaching a median depth of 22.2 mag and 22.2 mag respectively, and covering ~85% of the enclosed probability. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC (Masci et al. 2019). We queried the ZTF alert stream using Kowalski (Duev et al. 2019). We required at least 2 detections separated by at least 15 minutes to select against moving objects. Furthermore, we cross-matched our candidates with the Minor Planet Center to flag known asteroids, reject stellar sources (Tachibana and Miller 2018), and apply machine learning algorithms (Duev et al. 2019, Mahabal et al. 2019). We require no spatially coincident ZTF alert to be issued before the detection time of the GBM trigger. We identified 146 transient candidates located within the 95% probability contour of the skymap that passed automatic selection criteria. The majority of the transients showed no evolution between the two nights. We performed forced photometry (Masci et al. 2019) on the candidates reported below and found no previous history of variability. +--------------+-----------+-------------+--------------+--------+-------+-----------+ | Name | IAU Name | RA | Dec | disc. mag | notes | +--------------+-----------+-------------+--------------+--------+-------+-----------+ | ZTF21abcwmzx | AT2021nzo | 14:42:28.10 | +31:56:34.19 | g = 21.51 | (1)(e) | | ZTF21abcwnbm | AT2021nzp | 14:43:43.24 | +33:44:52.20 | g = 21.54 | (1)(d) | | ZTF21abcwuxv | AT2021nzq | 15:30:34.50 | +43:05:52.27 | r = 21.82 | (a)(b) | | ZTF21abcwvzr | AT2021nzr | 14:49:49.23 | +35:05:43.32 | r = 21.9 | (a)(e) | | ZTF21abcwwaj | AT2021nzs | 14:40:59.49 | +32:07:24.64 | r = 21.24 | (a)(c) | | ZTF21abcwyoe | AT2021nzt | 15:58:56.54 | +33:08:01.79 | r = 21.83 | (a)(d) | | ZTF21abcwyvi | AT2021nzu | 15:58:53.27 | +33:39:12.74 | r = 21.98 | (a)(b) | Notes: (1) shows rise and rapid decay (a) Non-detection during the second night (2021-05-31). These have two or more detections separated by >50 min during the first night. (b) hostless (c) host at z=0.1 (d) nuclear (e) likely offset from host Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, and IN2P3, France. Operations are conducted by COO, IPAC, and UW. -- Tomas Ahumada (he/him) Ph.D. Candidate Department of Astronomy University of Maryland, College Park NASA Goddard Space Flight Center, Code 661 B.Sc. Astronomy, Pontificia Universidad Católica de Chile