//////////////////////////////////////////////////////////////////////// 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: 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