August 2021 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 28632] Fermi GRB 210827B: Global MASTER-Net observations report
by GCN Circulars 28 Aug '21

28 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30735 SUBJECT: Fermi GRB 210827B: Global MASTER-Net observations report DATE: 21/08/28 12:30:29 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 210827B ( Fermi GBM team, GCN 30726) errorbox 24325 sec after notice time and 24337 sec after trigger time at 2021-08-27 16:55:53 UT, with upper limit up to 18.2 mag. Observations started at twilight. The observations began at zenith distance = 69 deg. The sun altitude is -11.4 deg. The galactic latitude b = -32 deg., longitude l = 26 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1701427 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 15633 | 2021-08-27 14:30:38 | MASTER- | (20h 28m 55.00s , -19d 15m 45.0s) | C | 20 | 15.2 | 16581 | 2021-08-27 14:46:27 | MASTER- | (20h 28m 52.92s , -19d 12m 38.6s) | C | 20 | 14.9 | 17531 | 2021-08-27 15:02:16 | MASTER- | (20h 28m 53.96s , -19d 13m 34.5s) | C | 20 | 15.0 | 18829 | 2021-08-27 15:23:55 | MASTER- | (20h 31m 16.41s , -17d 19m 29.2s) | C | 20 | 14.8 | 18829 | 2021-08-27 15:23:55 | MASTER- | (20h 23m 01.74s , -18d 44m 06.1s) | C | 20 | 13.7 | 19755 | 2021-08-27 15:39:20 | MASTER- | (20h 31m 06.85s , -17d 19m 50.6s) | C | 20 | 12.6 | 19755 | 2021-08-27 15:39:20 | MASTER- | (20h 22m 54.22s , -18d 43m 23.5s) | C | 20 | 13.5 | 20653 | 2021-08-27 15:54:19 | MASTER- | (20h 31m 05.17s , -17d 20m 21.3s) | C | 20 | 14.9 | 20653 | 2021-08-27 15:54:19 | MASTER- | (20h 22m 55.05s , -18d 42m 04.8s) | C | 20 | 13.2 | 24368 | 2021-08-27 16:55:53 | MASTER-Kislovodsk | (20h 27m 37.06s , -17d 37m 30.7s) | C | 60 | 16.9 | 24368 | 2021-08-27 16:55:53 | MASTER-Kislovodsk | (20h 32m 08.17s , -18d 03m 02.3s) | C | 60 | 17.1 | 24528 | 2021-08-27 16:58:34 | MASTER-Kislovodsk | (20h 25m 24.24s , -19d 31m 47.6s) | C | 60 | 17.0 | 24528 | 2021-08-27 16:58:34 | MASTER-Kislovodsk | (20h 29m 57.78s , -19d 57m 21.8s) | C | 60 | 17.4 | 25329 | 2021-08-27 17:11:55 | MASTER-Kislovodsk | (20h 27m 35.57s , -17d 37m 16.0s) | C | 60 | 17.3 | 25329 | 2021-08-27 17:11:55 | MASTER-Kislovodsk | (20h 32m 08.08s , -18d 02m 47.5s) | C | 60 | 17.9 | 25489 | 2021-08-27 17:14:35 | MASTER-Kislovodsk | (20h 25m 19.62s , -19d 33m 12.5s) | C | 60 | 17.3 | 25489 | 2021-08-27 17:14:35 | MASTER-Kislovodsk | (20h 29m 54.59s , -19d 58m 46.9s) | C | 60 | 17.9 | 26292 | 2021-08-27 17:27:57 | MASTER-Kislovodsk | (20h 27m 38.37s , -17d 37m 26.2s) | C | 60 | 17.4 | 26292 | 2021-08-27 17:27:57 | MASTER-Kislovodsk | (20h 32m 11.64s , -18d 02m 59.8s) | C | 60 | 18.2 | 26452 | 2021-08-27 17:30:37 | MASTER-Kislovodsk | (20h 25m 25.65s , -19d 31m 23.4s) | C | 60 | 17.5 | 26452 | 2021-08-27 17:30:37 | MASTER-Kislovodsk | (20h 30m 01.38s , -19d 56m 58.4s) | C | 60 | 18.1 | 27014 | 2021-08-27 17:39:59 | MASTER-Kislovodsk | (20h 31m 11.23s , -15d 44m 54.0s) | C | 60 | 17.5 | 27014 | 2021-08-27 17:39:59 | MASTER-Kislovodsk | (20h 35m 43.24s , -16d 10m 21.8s) | C | 60 | 18.2 | 27174 | 2021-08-27 17:42:40 | MASTER-Kislovodsk | (20h 24m 24.36s , -21d 25m 55.7s) | C | 60 | 17.5 | 27174 | 2021-08-27 17:42:40 | MASTER-Kislovodsk | (20h 29m 03.61s , -21d 51m 33.9s) | C | 60 | 18.1 | 27575 | 2021-08-27 17:49:20 | MASTER-Kislovodsk | (20h 41m 31.97s , -19d 31m 13.5s) | C | 60 | 17.5 | 27575 | 2021-08-27 17:49:20 | MASTER-Kislovodsk | (20h 46m 07.89s , -19d 56m 48.7s) | C | 60 | 18.2 | 27816 | 2021-08-27 17:53:21 | MASTER-Kislovodsk | (20h 43m 33.76s , -17d 38m 08.2s) | C | 60 | 17.5 | 27816 | 2021-08-27 17:53:21 | MASTER-Kislovodsk | (20h 48m 07.55s , -18d 03m 38.8s) | C | 60 | 18.1 | 27976 | 2021-08-27 17:56:02 | MASTER-Kislovodsk | (20h 31m 16.12s , -15d 44m 00.6s) | C | 60 | 17.6 | 27976 | 2021-08-27 17:56:02 | MASTER-Kislovodsk | (20h 35m 48.31s , -16d 09m 26.7s) | C | 60 | 18.2 | 28137 | 2021-08-27 17:58:42 | MASTER-Kislovodsk | (20h 24m 31.19s , -21d 26m 25.0s) | C | 60 | 17.5 | 28137 | 2021-08-27 17:58:43 | MASTER-Kislovodsk | (20h 29m 10.79s , -21d 52m 01.6s) | C | 60 | 18.2 | 28537 | 2021-08-27 18:05:23 | MASTER-Kislovodsk | (20h 46m 07.24s , -19d 56m 31.8s) | C | 60 | 18.0 | 28537 | 2021-08-27 18:05:23 | MASTER-Kislovodsk | (20h 41m 30.66s , -19d 30m 59.4s) | C | 60 | 17.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.

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[vsnet-grb-info 28631] GRB 210827A: Swift-XRT observations
by GCN Circulars 28 Aug '21

28 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30734 SUBJECT: GRB 210827A: Swift-XRT observations DATE: 21/08/28 08:58:36 GMT FROM: Paolo D'Avanzo at INAF - OAB <paolo.davanzo(a)inaf.it> J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), A. Tohuvavohu (U. Toronto) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Swift/BAT-GUANO-detected burst GRB 210827A (James DeLaunay et al. GCN Circ. 30732), collecting 2.3 ks of Photon Counting (PC) mode data between T0+44.4 ks and T0+50.4 ks. One uncatalogued X-ray source has been detected consistent with being within 296 arcsec of the Swift/BAT-GUANO position, 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 3: RA (J2000.0): 174.9003 = 11:39:36.07 Dec (J2000.0): +55.7239 = +55:43:26.2 Error: 3.8 arcsec (radius, 90% conf. [Enhanced position]) Count-rate: 0.0103 +/- 0.0025 ct s^-1 Distance: 225 arcsec from Swift/BAT-GUANO position. Flux: (4.8 +/- 1.2)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Four uncatalogued sources were also detected too far from the GRB position to be likely afterglow candidates. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021461. This circular is an official product of the Swift-XRT team.

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[vsnet-grb-info 28630] GRB 210827A: Swift ToO observations
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30733 SUBJECT: GRB 210827A: Swift ToO observations DATE: 21/08/27 22:02:28 GMT FROM: Phil Evans at U of Leicester <pae9(a)leicester.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 210827A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021461 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT-GUANO event. 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.

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[vsnet-grb-info 28629] GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30732 SUBJECT: GRB 210827A: Swift/BAT-GUANO detection and arcminute localization DATE: 21/08/27 21:41:58 GMT FROM: Aaron Tohuvavohu at U Toronto <aaron.tohu(a)gmail.com> James DeLaunay (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Aaron Tohuvavohu (U Toronto), report: Swift/BAT did not trigger on GRB 210827A (T0: 2021-08-27 09:59:24.34 UTC, Fermi/GBM trigger # 651751169, GCN 30724). The Fermi/GBM notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The burst is detected in BAT with a duration of approximately 10 seconds. Using the normal BAT imaging technique, we find the location for the GRB with an SNR of 8.3. The BAT position is RA, Dec = 174.9181 +55.7858 deg which is RA(J2000) = 11h 39m 40.34s Dec(J2000) = +55d 47′ 08.88″ with an estimated uncertainty of 4 arcmin. This position is consistent with the Fermi/GBM localization. XRT and UVOT follow-up has been requested. Results of follow-up observations will be reported in future circulars. GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/

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[vsnet-grb-info 28628]GRB 210820A: CAHA 2.2m Optical Detection
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30731 SUBJECT: GRB 210820A: CAHA 2.2m Optical Detection DATE: 21/08/27 18:03:36 GMT FROM: Alexander Kann at IAA-CSIC <kann(a)iaa.es> D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), C. Thoene, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), A. Fernandez, and I. Hermelo (all CAHA) report: We observed GRB 210820A (Swift detection: Beardmore et al., GCN #30664) with CAFOS mounted on the 2.2m CAHA telescope at Calar Alto, Alemria, Spain, under inclement conditions (bright moonlight, passing clouds, low transparency). We obtained 10 x 90 s each in filters B, V, Rc. Stacks reveal no detection of the afterglow in B (very shallow because of moonlight) and Rc (shallow because of incoming clouds which also prevented further observations). However, the afterglow (Beardmore et al., GCN #30664; Butler et al., GCN #30672; LaPorte & Beardmore, GCN #30686; Nicuesa Guelbenzu et al., GCN #30695) is clearly detected in V, somewhat north of a source also seen in Pan-STARRS and in SDSS. We find the afterglow to be V = 22.43 +/- 0.15 mag (AB mag, derived from two SDSS field stars transformed to V via the equations of Lupton 2005) at 0.43868 days after the GRB.

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[vsnet-grb-info 28627]GRB 210824A: Swift/UVOT Upper Limits
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30730 SUBJECT: GRB 210824A: Swift/UVOT Upper Limits DATE: 21/08/27 15:52:44 GMT FROM: Sam LaPorte at PSU <sjl5346(a)psu.edu> GRB 210824A: Swift/UVOT Upper Limits S. J. LaPorte (PSU) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 210824A 311 s after the BAT trigger (Page et al., GCN Circ. 30700). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 30702) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 311 461 147 >20.8 white 311 4350 364 >20.9 v 467 4760 236 >19.4 b 565 4145 235 >20.1 u 541 5220 83 >19.6 w1 516 5170 236 >20.4 m2 4765 4965 197 >20.3 w2 4356 4555 197 >19.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.037 in the direction of the burst (Schlegel et al. 1998).

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[vsnet-grb-info 28626]GRB 210826A: Swift/UVOT Upper Limits
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30729 SUBJECT: GRB 210826A: Swift/UVOT Upper Limits DATE: 21/08/27 15:38:05 GMT FROM: Alice Breeveld at MSSL-UCL <a.breeveld(a)ucl.ac.uk> A. A. Breeveld (UCL-MSSL) and T. Sbarrato (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 210826A 36747 s after the LAT trigger (Ohno et al., GCN Circ. 30721). No new optical source consistent with the any of the 8 candidate XRT positions (D'Ai et al., GCN Circ. 30725) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag v 36747 49716 4869 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.032 in the direction of the burst (Schlegel et al. 1998).

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[vsnet-grb-info 28625]POLAR detection of a SGR-like burst
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30728 SUBJECT: POLAR detection of a SGR-like burst DATE: 21/08/27 13:34:35 GMT FROM: Hancheng Li at IHEP/POLAR <lihc(a)ihep.ac.cn> G. Koziol (UniGE), H. C. Li (UniGE), M. Kole (UniGE), Y. H. Wang (IHEP), N. Produit (UniGE), J. C. Sun (IHEP) and Y. Zhao (IHEP/BNU) report on behalf of the POLAR collaboration: During on-ground blind search of archive POLAR data, we found a SGR-like burst whick took place on 2017-01-18 16:16:25.5 UT (T0). The burst has a duration (T90) of 0.32 +/- 0.02 seconds, the light curve and data files (both in ROOT and FITS formats) can be found at: https://www.astro.unige.ch/polar/content/sgr-candidate-170118 Using the localization method of POLAR (Y. H. Wang et al, 2021), the location of this event is best fitted as (in J2000): RA : 33.5 [deg] (l = 136.04) Dec: +50.7 [deg] (b = -10.06) Err: 8.1 [deg] (radius, 1 sigma containment, statistical only) The incident angle in the POLAR local coordinate at T0 is: Theta: 60.0 [deg] Phi: 50.0 [deg] The spectra is better fitted with "bbody+powerlaw" model than Band function or single powerlaw. The temperature (kT) is 13.85 +/- 0.79 keV with a normalization of 99.34 +/- 7.93, and the power law index is 1.73 +/- 0.43 with a normalization of 74.21 +/- 182.29. The fluence (50-500 keV) from T0 to T0 + 1.0 s is (5.09 +/- 1.33) E-06 erg/cm^2, and the average photon flux (50-500 keV) over this time period is 40 +/- 1 ph/s/cm^2. The results presented above are preliminary. Refined analyses are ongoing. Additionally, more burst events are expected to be found in the blind search of data which was recently started, and to be circulated by GCN. POLAR was a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) on Sep 15, 2016, and ended operation in April 2017. More information about POLAR can be found at https://www.astro.unige.ch/polar/ , http://polar.ihep.ac.cn/en/ , and http://polar.psi.ch/html/ .

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[vsnet-grb-info 28624]GRB 210827B: BALROG localization (Fermi Trigger 651751821 / GRB 210827424)
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30727 SUBJECT: GRB 210827B: BALROG localization (Fermi Trigger 651751821 / GRB 210827424) DATE: 21/08/27 10:28:30 GMT FROM: Jochen Greiner at MPE,Garching <jcg(a)mpe.mpg.de> J. Burgess, F. Kunzweiler, B. Biltzinger, F. Berlato, & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 651751821 at 10:10:16 on 27 Aug. 2021 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position (1 sigma statistical errors) is: RA(2000.0) = 305.1+/-2.9 deg Decl.(2000.0) = -17.3+/-2.3 deg We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB210827424/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB210827424/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB210827424/json

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[vsnet-grb-info 28623]GRB 210827B: Fermi GBM Final Real-time Localization
by GCN Circulars 27 Aug '21

27 Aug '21

TITLE: GCN CIRCULAR NUMBER: 30726 SUBJECT: GRB 210827B: Fermi GBM Final Real-time Localization DATE: 21/08/27 10:20:35 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 10:10:16 UT on 27 Aug 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210827B (trigger 651751821.143562 / 210827424). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 308.8, Dec = -19.3 (J2000 degrees, equivalent to J2000 20h 35m, -19d 18'), with a statistical uncertainty of 2.5 degrees. The angle from the Fermi LAT boresight is 66.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210827424/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210827424/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210827424/…

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