//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30285 SUBJECT: GRB 210621A: Fermi GBM Final Real-time Localization DATE: 21/06/21 10:54:22 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely SHORT GRB At 10:44:03 UT on 21 Jun 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210621A (trigger 645965048.749786 / 210621447). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 248.3, Dec = -61.1 (J2000 degrees, equivalent to J2000 16h 33m, -61d 06'), with a statistical uncertainty of 8.6 degrees. The angle from the Fermi LAT boresight is 78.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210621447/quicklook/glg_skymap_all_bn210621447.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/bn210621447/quicklook/glg_healpix_all_bn210621447.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210621447/quicklook/glg_lc_medres34_bn210621447.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30287 SUBJECT: Fermi GRB 210621A: Global MASTER-Net observations report DATE: 21/06/21 12:51:43 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-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 Fermi GRB 210621A ( Fermi GBM team, GCN 30285) errorbox 353 sec after notice time and 399 sec after trigger time at 2021-06-21 10:50:43 UT, with upper limit up to 15.2 mag. Observations started at twilight. The observations began at zenith distance = 75 deg. The sun altitude is -9.0 deg. The galactic latitude b = -9 deg., longitude l = 327 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1641646 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 430 | 2021-06-21 10:50:43 | MASTER-OAFA | (16h 35m 08.88s , -58d 53m 13.5s) | C | 60 | 15.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30295 SUBJECT: Swift GRB210621.71: Global MASTER-Net observations report DATE: 21/06/21 17:17:26 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB210621.71 (trigger No 1057131,15h 55m 14.88s , -54d 03m 46.8s, R=0.05) errorbox 79 sec after trigger time at 2021-06-21 17:05:55 UT, with upper limit up to 16.6 mag. The observations began at zenith distance = 43 deg. The sun altitude is -17.3 deg. The galactic latitude b = -1 deg., longitude l = 328 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1641828 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 89 | MASTER-SAAO | P\ | 20 | 15.6 | 129 | MASTER-SAAO | P\ | 20 | 16.0 | 173 | MASTER-SAAO | P\ | 30 | 16.1 | 228 | MASTER-SAAO | P\ | 40 | 15.6 | 292 | MASTER-SAAO | P\ | 50 | 16.6 | 372 | MASTER-SAAO | P\ | 70 | 16.6 | The observation and reduction will continue. The message may be cited.