//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29219 SUBJECT: Swift GRB210102.01: Global MASTER-Net observations report DATE: 21/01/02 00:24:22 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 GRB210102.01 (trigger No 1015615,15h 38m 48.72s , -84d 11m 20.4s, R=0.05) errorbox 70 sec after trigger time at 2021-01-02 00:18:22 UT, with upper limit up to 13.5 mag. The observations began at zenith distance = 60 deg. The sun altitude is -30.5 deg. The galactic latitude b = -23 deg., longitude l = 307 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1517044 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 75 | MASTER-SAAO | P\ | 10 | 13.2 | 109 | MASTER-SAAO | P\ | 20 | 13.5 | 154 | MASTER-SAAO | P\ | 30 | 13.3 | 273 | MASTER-SAAO | P\ | 50 | 13.3 | The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29223 SUBJECT: GRB 210102B: MAXI/GSC detection DATE: 21/01/02 12:38:16 GMT FROM: Motoko Serino at RIKEN/MAXI C. Guo (RIKEN), M. Serino (AGU), H. Negoro, M. Nakajima, M. Aoki, K. Kobayashi, R. Takagi, K, Asakura, K, Seino (Nihon U.), T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, H. Nishida, K. Komachi, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.), M. Shidatsu (Ehime U.), N. Kawai, R. Adachi, M. Niwano, R. Hosokawa (Tokyo Tech), S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA), Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake, U. Goto, R. Uematsu (Kyoto U.), H. Tsunemi (Osaka U.), M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC) report on behalf of the MAXI team: The MAXI/GSC nova alert system triggered on a bright uncatalogued X-ray transient source at 2021-01-02T09:03:48 UT. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (353.323 deg, -21.086 deg) = (23 33 18, -21 05 10) (J2000) with a statistical 90% C.L. circular error region with a radius of 0.5 deg. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 238 +- 31 mCrab (2.0-4.0keV, 1 sigma error). There was no significant excess flux in the next transit at 10:36 UT with an upper limit of 20 mCrab. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29224 SUBJECT: GRB 210102B: Tiled Swift observations DATE: 21/01/02 14:40:06 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the MAXI GRB 210102B. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00097 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the MAXI event is high: any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29225 SUBJECT: MAXI GRB210102.38: Global MASTER-Net observations report DATE: 21/01/02 15:51:10 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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the MAXI GRB210102.38 (trigger No 216347865,23h 33m 17.52s , -21d 05m 09.6s, R=1) errorbox 20657 sec after notice time and 22218 sec after trigger time at 2021-01-02 15:14:28 UT, with upper limit up to 18.6 mag. Observations started at twilight. The observations began at zenith distance = 66 deg. The sun altitude is -10.2 deg. The galactic latitude b = -72 deg., longitude l = 49 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1517221 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 22308 | 2021-01-02 15:14:28 | MASTER-Tavrida | (23h 38m 28.04s , -21d 16m 44.6s) | C | 180 | 16.5 | 22447 | 2021-01-02 15:17:47 | MASTER-Tavrida | (23h 40m 11.97s , -22d 12m 44.8s) | C | 60 | 16.8 | 22447 | 2021-01-02 15:17:47 | MASTER-Tavrida | (23h 33m 48.28s , -22d 08m 48.5s) | C | 60 | 17.1 | 23188 | 2021-01-02 15:29:07 | MASTER-Tavrida | (23h 38m 29.61s , -21d 16m 08.3s) | C | 180 | 18.0 | 23188 | 2021-01-02 15:29:07 | MASTER-Tavrida | (23h 32m 05.67s , -21d 12m 28.7s) | C | 180 | 17.8 | 23327 | 2021-01-02 15:32:27 | MASTER-Tavrida | (23h 38m 17.21s , -20d 11m 56.3s) | C | 60 | 17.9 | 23327 | 2021-01-02 15:32:27 | MASTER-Tavrida | (23h 31m 55.64s , -20d 08m 18.0s) | C | 60 | 18.3 | 23407 | 2021-01-02 15:33:46 | MASTER-Tavrida | (23h 40m 12.49s , -22d 11m 02.2s) | C | 60 | 18.0 | 23407 | 2021-01-02 15:33:46 | MASTER-Tavrida | (23h 33m 45.80s , -22d 07m 25.1s) | C | 60 | 18.4 | 23546 | 2021-01-02 15:35:05 | MASTER-Tavrida | (23h 38m 28.70s , -21d 17m 17.2s) | C | 180 | 18.6 | 23546 | 2021-01-02 15:35:05 | MASTER-Tavrida | (23h 32m 04.24s , -21d 13m 40.4s) | C | 180 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29226 SUBJECT: GRB 210102C: Swift detection of a burst DATE: 21/01/02 20:47:29 GMT FROM: David Palmer at LANL E. Troja (NASA/GSFC/UMCP), M. G. Bernardini (INAF-OAB), C. Gronwall (PSU), A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), D. M. Palmer (LANL) and T. Sbarrato (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team: At 20:38:11 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210102C (trigger=1015728). Swift did not slew due to an observing constraint. The BAT on-board calculated location is RA, Dec 235.737, -37.222 which is RA(J2000) = 15h 42m 57s Dec(J2000) = -37d 13' 19" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 100 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~65 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 15:14 UT on 2021 January 06. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29227 SUBJECT: Swift GRB 210102C: Global MASTER-Net observations report DATE: 21/01/03 00:56:12 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 GRB 210102C ( E. Troja et al., GCN 29226) errorbox 14718 sec after notice time and 14840 sec after trigger time at 2021-01-03 00:45:31 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 78 deg. The sun altitude is -27.8 deg. The galactic latitude b = 14 deg., longitude l = 337 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1517509 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 14931 | MASTER-SAAO | C | 180 | 17.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29228 SUBJECT: GRB 210102C: Fermi GBM detection DATE: 21/01/03 06:07:38 GMT FROM: Suraj Poolakkil at UAH S. Poolakkil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 20:39:14.40 UT on 2 January 2021, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 210102C (trigger 631312759 / 210102861), which was also detected by the Swift/BAT (Troja et al. 2021, GCN 29226); GBM triggered on a later, brighter emission. The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 131 degrees. The GBM light curve consists of multiple peaks followed by some extended emission with a duration (T90) of about 84 s (50-300 keV). The time-averaged spectrum from T0-3.07 s to T0+9.22 s (bright emission which triggered GBM) is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.41 +/- 0.08 and the cutoff energy, parameterized as Epeak, is 209 +/- 39 keV. The event fluence (10-1000 keV) in this time interval is (5.219 +/- 0.332)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.99 s in the 10-1000 keV band is 7.9 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29229 SUBJECT: Fermi GRB 210102C: Global MASTER-Net observations report DATE: 21/01/03 08:45:09 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) started inspect of the Fermi GRB 210102C ( S. Poolakkil et al., GCN 29228) errorbox 14713 sec after notice time and 14777 sec after trigger time at 2021-01-03 00:45:31 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 78 deg. The sun altitude is -27.8 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 210102C errorbox 37485 sec after notice time and 37549 sec after trigger time at 2021-01-03 07:05:03 UT, with upper limit up to 17.4 mag. The observations began at zenith distance = 75 deg. The sun altitude is -25.8 deg. The galactic latitude b = 14 deg., longitude l = 341 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1517531 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 14868 | 2021-01-03 00:45:31 | MASTER-SAAO | (15h 37m 40.48s , -37d 10m 22.5s) | C | 180 | 17.5 | 15229 | 2021-01-03 00:51:33 | MASTER-SAAO | (15h 37m 40.65s , -37d 11m 17.2s) | C | 180 | 17.7 | 15508 | 2021-01-03 00:56:12 | MASTER-SAAO | (15h 37m 43.87s , -37d 11m 02.4s) | C | 180 | 17.7 | 37639 | 2021-01-03 07:05:03 | MASTER-OAFA | (15h 41m 31.97s , -37d 50m 25.5s) | C | 180 | 16.9 | 38059 | 2021-01-03 07:12:02 | MASTER-OAFA | (15h 41m 30.60s , -37d 52m 29.2s) | C | 180 | 17.2 | 38563 | 2021-01-03 07:20:27 | MASTER-OAFA | (15h 41m 33.22s , -37d 52m 25.5s) | C | 180 | 17.2 | 38932 | 2021-01-03 07:27:35 | MASTER-OAFA | (15h 58m 44.82s , -34d 37m 34.2s) | C | 60 | 16.9 | 39011 | 2021-01-03 07:28:55 | MASTER-OAFA | (15h 39m 27.24s , -34d 39m 06.6s) | C | 60 | 17.3 | 39091 | 2021-01-03 07:30:14 | MASTER-OAFA | (15h 56m 09.32s , -32d 37m 35.3s) | C | 60 | 16.9 | 39170 | 2021-01-03 07:31:34 | MASTER-OAFA | (15h 43m 02.44s , -36d 37m 27.2s) | C | 60 | 17.2 | 39249 | 2021-01-03 07:32:53 | MASTER-OAFA | (15h 37m 14.21s , -32d 36m 54.4s) | C | 60 | 17.2 | 39329 | 2021-01-03 07:34:12 | MASTER-OAFA | (16h 02m 42.12s , -36d 39m 25.7s) | C | 60 | 17.0 | 39408 | 2021-01-03 07:35:32 | MASTER-OAFA | (15h 47m 50.85s , -38d 37m 22.4s) | C | 60 | 16.9 | 39488 | 2021-01-03 07:36:52 | MASTER-OAFA | (15h 54m 49.80s , -30d 37m 41.3s) | C | 60 | 16.9 | 39886 | 2021-01-03 07:43:30 | MASTER-OAFA | (15h 58m 45.09s , -34d 38m 17.8s) | C | 60 | 17.0 | 39966 | 2021-01-03 07:44:49 | MASTER-OAFA | (16h 08m 24.29s , -34d 37m 29.7s) | C | 60 | 16.8 | 40045 | 2021-01-03 07:46:09 | MASTER-OAFA | (15h 39m 33.51s , -34d 37m 53.1s) | C | 60 | 17.3 | 40124 | 2021-01-03 07:47:28 | MASTER-OAFA | (15h 49m 07.52s , -34d 39m 05.9s) | C | 60 | 17.1 | 40205 | 2021-01-03 07:48:49 | MASTER-OAFA | (15h 56m 13.18s , -32d 38m 48.1s) | C | 60 | 17.1 | 40285 | 2021-01-03 07:50:09 | MASTER-OAFA | (16h 05m 35.69s , -32d 37m 31.1s) | C | 60 | 16.8 | 40365 | 2021-01-03 07:51:29 | MASTER-OAFA | (15h 42m 59.86s , -36d 38m 48.3s) | C | 60 | 17.2 | 40444 | 2021-01-03 07:52:48 | MASTER-OAFA | (15h 52m 56.54s , -36d 37m 37.3s) | C | 60 | 17.1 | 40524 | 2021-01-03 07:54:07 | MASTER-OAFA | (15h 37m 15.85s , -32d 37m 51.2s) | C | 60 | 17.3 | 40603 | 2021-01-03 07:55:27 | MASTER-OAFA | (15h 46m 40.83s , -32d 37m 04.2s) | C | 60 | 17.2 | 40683 | 2021-01-03 07:56:47 | MASTER-OAFA | (16h 02m 48.12s , -36d 38m 26.4s) | C | 60 | 17.1 | 40842 | 2021-01-03 07:59:26 | MASTER-OAFA | (15h 47m 53.41s , -38d 38m 51.7s) | C | 60 | 17.0 | 40928 | 2021-01-03 08:00:52 | MASTER-OAFA | (15h 57m 59.44s , -38d 37m 42.7s) | C | 60 | 16.7 | 41009 | 2021-01-03 08:02:12 | MASTER-OAFA | (15h 54m 46.80s , -30d 38m 46.7s) | C | 60 | 17.0 | 41088 | 2021-01-03 08:03:32 | MASTER-OAFA | (16h 04m 03.97s , -30d 37m 57.6s) | C | 60 | 16.9 | 41406 | 2021-01-03 08:08:50 | MASTER-OAFA | (15h 33m 02.59s , -36d 38m 51.3s) | C | 60 | 17.2 | 41565 | 2021-01-03 08:11:29 | MASTER-OAFA | (15h 45m 32.45s , -30d 37m 17.1s) | C | 60 | 17.3 | 41803 | 2021-01-03 08:15:27 | MASTER-OAFA | (15h 58m 44.22s , -34d 38m 25.6s) | C | 60 | 17.2 | 41883 | 2021-01-03 08:16:47 | MASTER-OAFA | (16h 08m 22.62s , -34d 37m 38.5s) | C | 60 | 17.0 | 41964 | 2021-01-03 08:18:08 | MASTER-OAFA | (15h 39m 33.08s , -34d 37m 59.5s) | C | 60 | 17.4 | 42044 | 2021-01-03 08:19:28 | MASTER-OAFA | (15h 49m 05.56s , -34d 39m 13.0s) | C | 60 | 17.2 | 42123 | 2021-01-03 08:20:47 | MASTER-OAFA | (15h 56m 11.34s , -32d 39m 21.9s) | C | 60 | 17.0 | 42202 | 2021-01-03 08:22:06 | MASTER-OAFA | (16h 05m 34.89s , -32d 37m 49.7s) | C | 60 | 16.8 | 42282 | 2021-01-03 08:23:26 | MASTER-OAFA | (15h 42m 58.96s , -36d 39m 00.0s) | C | 60 | 17.1 | 42361 | 2021-01-03 08:24:45 | MASTER-OAFA | (15h 52m 54.79s , -36d 37m 30.0s) | C | 60 | 16.9 | 42440 | 2021-01-03 08:26:04 | MASTER-OAFA | (15h 37m 14.12s , -32d 37m 56.0s) | C | 60 | 17.2 | 42520 | 2021-01-03 08:27:24 | MASTER-OAFA | (15h 46m 40.09s , -32d 37m 09.0s) | C | 60 | 16.9 | 42600 | 2021-01-03 08:28:43 | MASTER-OAFA | (16h 02m 47.44s , -36d 38m 32.4s) | C | 60 | 16.9 | 42679 | 2021-01-03 08:30:03 | MASTER-OAFA | (16h 12m 34.07s , -36d 39m 45.9s) | C | 60 | 16.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29230 SUBJECT: GRB 210102B: Swift-XRT observations DATE: 21/01/03 13:44:24 GMT FROM: Paolo D'Avanzo at INAF - OAB D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the MAXI-detected burst GRB 210102B (Guo et al. GCN Circ. 29223) in a series of observations tiled on the sky. The total exposure time is 1.3 ks, distributed over 7 tiles; the maximum exposure at a single sky location was 406 s. The data were collected between T0+19.7 ks and T0+26.0 ks, and are entirely in Photon Counting (PC) mode. One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 1: RA (J2000.0): 353.8173 = 23:35:16.14 Dec (J2000.0): -21.0821 = -21:04:55.6 Error: 5.5 arcsec (radius, 90% conf.) Count-rate: 0.030 [+0.016, -0.012] ct s^-1 Distance: 1289 arcsec from MAXI position. The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00097. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29231 SUBJECT: GRB 210102C: Swift-BAT refined analysis DATE: 21/01/03 23:41:32 GMT FROM: Amy Lien at GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+537 sec from the recent telemetry downlink, we report further analysis of BAT GRB 210102C (trigger #1015728) (Troja et al., GCN Circ. 29226). The BAT ground-calculated position is RA, Dec = 235.747, -37.231 deg which is RA(J2000) = 15h 42m 59.2s Dec(J2000) = -37d 13' 52.2" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 76%. The mask-weighted light curve shows a double-peaked structure. The first peak starts at ~T-2 s, peaks at ~T0, and ends at ~T+8 s. The second peak starts at ~T+55 s, peaks at ~T+67 s, and ends at ~T+100 s. T90 (15-350 keV) is 87.25 +- 4.97 sec (estimated error including systematics). The time-averaged spectrum from T-2.07 to T+97.42 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.87 +- 0.08. The fluence in the 15-150 keV band is 3.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+66.72 sec in the 15-150 keV band is 4.4 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/BATbursts/1015728/bascript/top.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29240 SUBJECT: GRB 210102B: Assy optical observations DATE: 21/01/04 18:06:38 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), S. Belkin (IKI), V. Kim (FAI, Pulkovo Observatory), M. Krugov (FAI) report on behalf of GRB IKI FuN: We observed MAXI GRB 210102B (Guo et al., GCN 29223) with AZT-20 telescope of Assy-Turgen observatory starting on Jan. 03 (UT) 13:00:53. i.e. ~1.6 days after trigger. At the place of the only one of XRT candidates (Burrows et al., GCN 29230) in the localization area of MAXI (Guo et al., GCN 29223) we clearly detect the optical object in coordinates (J2000) 23:35:15.88 -21:04:55.5 with uncertainness of 0.6 arcsec in both coordinates. Preliminary photometry of the object is following Date UT start t-T0 Filter Exp. OT Err. UL (3sigma) (mid, days) (s) 2021-01-03 13:00:53 1.19068 r'(AB) 75*60 22.2 0.2 23.0 The photometry is based on the stars of PanSTARRS-PS1 RA DEC r' 23:35:20.67802 -21:04:16.4688 19.656 23:35:47.99017 -21:11:53.6544 17.807 At this tome we cannot confirm variability of the source. We can suggest the object might be related to GRB 210102B. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29244 SUBJECT: GRB 210102B: Tiled Swift observations DATE: 21/01/04 21:35:37 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the MAXI GRB 210102B. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00098 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the MAXI event is high: any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29270 SUBJECT: GRB 210102B: Assy optical afterglow identification DATE: 21/01/06 15:55:15 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), S. Belkin (IKI), V. Kim (FAI, Pulkovo Observatory), M. Krugov (FAI) report on behalf of GRB IKI FuN: We continued observations of XRT candidate (Burrows et al., GCN 29230) of MAXI GRB 210102B (Guo et al., GCN 29223) with AZT-20 telescope of Assy-Turgen observatory starting on Jan. 05 (UT) 13:00:53, i.e. ~3.2 days after trigger. At the place of the only one of XRT candidate (Burrows et al., GCN 29230) we do not detect the optical object found early (Pozanenko et al., GCN 29240). Preliminary photometry of the field is following Date UT start t-T0 Filter Exp. OT Err. UL (3sigma) (mid, days) (s) 2021-01-05 13:00:53 3.20177 r'(AB) 76*60 n/d n/d 23.1 The photometry is based on the stars of PanSTARRS-PS1 RA DEC r' 23:35:20.67802 -21:04:16.4688 19.656 23:35:47.99017 -21:11:53.6544 17.807 We confirm the optical object reported in GCN 29240 as an afterglow of GRB 210102B. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29271 SUBJECT: GRB 210102B: further Swift-XRT observations DATE: 21/01/06 17:28:28 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, M.G. Bernardini, A. Melandri, T. Sbarrato (INAF-OAB), P.A. Evans (U. Leicester) and A. Y. Lien (GSFC/UMBC) report on behalf of the Swift-XRT team: Swift-XRT obtained further observations of the field of the MAXI-detected burst GRB 210102B (Guo et al. GCN Circ. 29223). The data were collected between T0+209.5 ks and T0+312.5 ks for a total exposure time of 2.5 ks, and are entirely in Photon Counting (PC) mode. Source 1 (Burrows et al., GCN Circ. 29230) is not detected down to a 3sigma upper limit of 0.004 ct/s. The source therefore has faded (with 2.2 sigma significance) with respect to the previous detection level (0.030 [+0.016, -0.012] ct s^-1 between T0+19.7 ks and T0+26.0 ks; Burrows et al., GCN Circ. 29230). We propose this source as the GRB X-ray afterglow, in agreement with the results of the optical observations reported by Pozanenko et al. (GCN Circ. 29270).