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

[vsnet-grb-info 28750] GRB 210919B: Fermi GBM Final Real-time Localization
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30853 SUBJECT: GRB 210919B: Fermi GBM Final Real-time Localization DATE: 21/09/19 15:51:07 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 SHORT GRB At 15:39:51 UT on 19 Sep 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210919B (trigger 653758796.95736 / 210919653). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 215.2, Dec = -77.1 (J2000 degrees, equivalent to J2000 14h 20m, -77d 05'), with a statistical uncertainty of 9.2 degrees. The angle from the Fermi LAT boresight is 53.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210919653/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210919653/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210919653/…

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[vsnet-grb-info 28749] GRB 210919A: NOT upper limits
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30852 SUBJECT: GRB 210919A: NOT upper limits DATE: 21/09/19 12:24:18 GMT FROM: Daniel Perley at Liverpool JMU <d.a.perley(a)ljmu.ac.uk> D. A. Perley (LJMU), Z. P. Zhu (NAOC, HUST), D. Xu, S.Y. Fu (NAOC), D. B. Malesani (DTU Space), and A. Avramova-Boncheva (NOT) report: We observed the field of GRB210919A (Tohuvavohu et al. GCN 30846) using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. We obtained 3x300s frames in the Sloan r-band filter and 5x240s in the i-band filter. Observations were carried out on 2021-09-19 between 03:29 and 04:08 UT. No source is detected inside the enhanced XRT error circle (Goad et al., GCN 30850), to 3-sigma limits of: r>23.4 mag (at t=3.15 hours post-trigger) and i>23.9 (at t=3.47 hours post-trigger). DisclaimerNone

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[vsnet-grb-info 28748] GRB 210919A: AbAO optical upper limit
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30851 SUBJECT: GRB 210919A: AbAO optical upper limit DATE: 21/09/19 09:24:53 GMT FROM: Alexei Pozanenko at IKI, Moscow <apozanen(a)iki.rssi.ru> N. Pankov (HSE, IKI), R. Ya. Inasaridze (AbAO), A. Pozanenko (IKI), S. Belkin (IKI), D. Datashvili (AbAO), V. R. Ayvazian (AbAO), G. V. Kapanadze (AbAO) report on behalf of GRB IKI FuN: We observed the field of Swift short GRB 210919A (Tohuvavohu et al. GCN 30846) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on Sep., 19 (UT) 00:48:33. We do not detect any object in the enhanced XRT position (Goad et al. GCN 30850). This is consistent with optical observations (Tohuvavohu et al. GCN 30846; Lipunov et al., GCN 30847; Hu et al. GCN 30848; Strausbaugh et al. GCN 30849). Preliminary photometry of the field is following Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2021-09-19 00:48:33 0.03194 R 52*60 n/d n/d 22.1 The photometry is based on the nearby SDSS stars: SDSS-DR12 R(Lupton) 5:21:01.5917 +1:18:14.862 17.82 5:20:58.8314 +1:18:59.733 18.36

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[vsnet-grb-info 28747] GRB 210919A: Enhanced Swift-XRT position
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30850 SUBJECT: GRB 210919A: Enhanced Swift-XRT position DATE: 21/09/19 05:06:55 GMT FROM: Phil Evans at U of Leicester <pae9(a)leicester.ac.uk> M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 453 s of XRT Photon Counting mode data and 1 UVOT images for GRB 210919A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 80.25448, +1.31153 which is equivalent to: RA (J2000): 05h 21m 1.08s Dec (J2000): +01d 18' 41.5" with an uncertainty of 4.6 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.

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[vsnet-grb-info 28746] GRB 210919A: LCO Optical Upper Limit
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30849 SUBJECT: GRB 210919A: LCO Optical Upper Limit DATE: 21/09/19 04:55:40 GMT FROM: Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh(a)uvi.edu> R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration: We observed Swift GRB 210919A (Tohuvavohu, et al., GCN 30846) with the LCO 1-m Sinistro instrument at the South African Astronomical Observatory site, on September 19, from 01:41 to 02:08 UT (corresponding to 1.22 to 1.67 hours from the GRB trigger time) with the Bessel R and I filters. We performed a series of 4x200s exposures in R and 3x200s in I. In the large XRT detection region (Tohuvavohu, et al., GCN 30846) we find no obvious optical counterpart could be detected down to the following upper limits (consistent with previous reports (Tohuvavohu et al., GCNC 30846; Lipunov et al., GCNC 30847; Hu et al., GCN 30848)), calculated using the USNO-B.1 catalog as reference: R>20.5 I>18.7 These magnitudes are not corrected for galactic extinction. R.S. is funded by NSF AST grant #1831682

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[vsnet-grb-info 28745] GRB 210919A: BOOTES-2/TELMA optical upper limit
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30848 SUBJECT: GRB 210919A: BOOTES-2/TELMA optical upper limit DATE: 21/09/19 01:57:54 GMT FROM: Youdong HU at IAA-CSIC <huyoudong072(a)hotmail.com> Y.-D. Hu, T.-R. Sun, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC) and M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report: The 60cm BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) automatically responded to the Swift trigger of short GRB 210919A (Tohuvavohu et al. GCNC 30846). Images were taken starting at 00:32 UT on 19 Sep (~4 min after trigger) under high airmass conditions. In the co-added 10 x 10 s exposure image (clear filter), no optical afterglow is detected within the reported XRT/Swift source position (Tohuvavohu et al. GCNC 30846) down to 17.5 mag. This non-detection is consistent with reports from Tohuvavohu et al.(GCNC 30846) and Lipunov et al.(GCNC 30847). We thank the staff at La Mayora for its excellent support.

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[vsnet-grb-info 28744] Swift GRB 210919A: Global MASTER-Net observations report
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30847 SUBJECT: Swift GRB 210919A: Global MASTER-Net observations report DATE: 21/09/19 01:48:24 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-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 210919A ( A. Tohuvavohu et al., GCN 30846) errorbox 47 sec after trigger time at 2021-09-19 00:29:20 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 61 deg. The sun altitude is -49.0 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB 210919A errorbox 363 sec after notice time and 790 sec after trigger time at 2021-09-19 00:41:44 UT, with upper limit up to 14.3 mag. The observations began at zenith distance = 50 deg. The sun altitude is -24.1 deg. The galactic latitude b = -19 deg., longitude l = 201 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1725958 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 52 | MASTER-SAAO | P\ | 10 | 16.1 | 67 | MASTER-SAAO | P\ | 40 | 17.0 | Coadd 397 | MASTER-SAAO | P\ | 700 | 18.4 | Coadd 77 | MASTER-SAAO | P\ | 10 | 16.4 | 103 | MASTER-SAAO | P\ | 20 | 16.6 | 141 | MASTER-SAAO | P\ | 30 | 16.0 | 176 | MASTER-SAAO | P\ | 100 | 16.6 | Coadd 183 | MASTER-SAAO | P\ | 30 | 14.7 | 230 | MASTER-SAAO | P\ | 40 | 16.4 | 288 | MASTER-SAAO | P\ | 50 | 15.9 | 358 | MASTER-SAAO | P\ | 190 | 16.6 | Coadd 355 | MASTER-SAAO | P\ | 60 | 15.1 | 437 | MASTER-SAAO | P\ | 80 | 16.4 | 541 | MASTER-SAAO | P\ | 100 | 17.8 | 676 | MASTER-SAAO | P\ | 370 | 18.6 | Coadd 662 | MASTER-SAAO | P\ | 120 | 17.8 | 810 | MASTER-SAAO | P\ | 150 | 18.1 | 871 | MASTER-Kislovodsk | P| | 160 | 14.2 | 987 | MASTER-SAAO | P\ | 180 | 17.5 | 1167 | MASTER-SAAO | P\ | 540 | 17.9 | Coadd 1048 | MASTER-Kislovodsk | P- | 180 | 12.4 | 1048 | MASTER-Kislovodsk | P| | 180 | 14.1 | 1188 | MASTER-SAAO | P\ | 180 | 17.4 | 1249 | MASTER-Kislovodsk | P- | 180 | 12.9 | 1249 | MASTER-Kislovodsk | P| | 180 | 14.2 | 1387 | MASTER-SAAO | P\ | 180 | 17.4 | 1449 | MASTER-Kislovodsk | P- | 180 | 13.4 | 1449 | MASTER-Kislovodsk | P| | 180 | 14.3 | 1587 | MASTER-SAAO | P\ | 180 | 17.4 | 1650 | MASTER-Kislovodsk | P- | 180 | 13.6 | The observation and reduction will continue. The message may be cited.

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[vsnet-grb-info 28743] GRB 210919A: Swift detection of a short burst
by GCN Circulars 19 Sep '21

19 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30846 SUBJECT: GRB 210919A: Swift detection of a short burst DATE: 21/09/19 00:54:18 GMT FROM: Scott Barthelmy at NASA/GSFC <scott(a)milkyway.gsfc.nasa.gov> A. Tohuvavohu (U Toronto), S. D. Barthelmy (GSFC), A. Y. Lien (U Tampa) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 00:28:33 UT, the Swift Burst Alert Telescope (BAT) triggered and located a short GRB 210919A (trigger=1073893). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 80.230, +1.274 which is RA(J2000) = 05h 20m 55s Dec(J2000) = +01d 16' 27" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 0.3 sec. The peak count rate was ~3500 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 00:30:10.5 UT, 97.0 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 80.25441, 1.31189 which is equivalent to: RA(J2000) = 05h 21m 01.06s Dec(J2000) = +01d 18' 42.8" with an uncertainty of 6.9 arcseconds (radius, 90% containment). This location is 162 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.56 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 99 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.142. Burst Advocate for this burst is A. Tohuvavohu (tohuvavohu AT astro.utoronto.ca). 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/)

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[vsnet-grb-info 28742] Swift trigger 1073821: detection of IGR J16418-4532
by GCN Circulars 18 Sep '21

18 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30845 SUBJECT: Swift trigger 1073821: detection of IGR J16418-4532 DATE: 21/09/18 08:23:26 GMT FROM: Scott Barthelmy at NASA/GSFC <scott(a)milkyway.gsfc.nasa.gov> S. D. Barthelmy (GSFC), K. L. Page (U Leicester) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 07:58:20 UT, the Swift Burst Alert Telescope (BAT) triggered and located IGR J16418-4532 (trigger=1073821). Swift slewed immediately to the source. The BAT on-board calculated location is RA, Dec 250.455, -45.540 which is RA(J2000) = 16h 41m 49s Dec(J2000) = -45d 32' 22" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve is an image trigger and as such does not show any peak. The XRT began observing the field at 08:00:28.1 UT, 128.0 seconds after the BAT trigger. XRT found a bright X-ray source located at RA, Dec 250.4669, -45.5421 which is equivalent to: RA(J2000) = 16h 41m 52.06s Dec(J2000) = -45d 32' 31.6" with an uncertainty of 4.9 arcseconds (radius, 90% containment). This location is 30 arcseconds from the BAT onboard position, within the BAT error circle. This position is 15.1 arcseconds from a known X-ray source: 2SXPS J164150.7-453225, also known as IGRJ16418-4532. This source is in the Swift XRT 2SXPS catalogue with a mean 0.3-10 keV count-rate of 0.2893 +/- 0.0028 ct/sec; see https://www.swift.ac.uk/2SXPS/2SXPS%20J164150.7-453225 for details of these previous observations. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 250 seconds with the U filter starting 133 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The coverage of the XRT error circle by the 8'x8' region for the list of sources generated on-board is uncertain because the large number of sources filled the available telemetry. The list of sources is typically complete to about 18.0 mag. No correction has been made for the large, but uncertain, extinction expected.

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[vsnet-grb-info 28741] GRB 210912A: BOOTES-5/JGT optical afterglow candidate (Correction to GCNC 30823)
by GCN Circulars 17 Sep '21

17 Sep '21

TITLE: GCN CIRCULAR NUMBER: 30844 SUBJECT: GRB 210912A: BOOTES-5/JGT optical afterglow candidate (Correction to GCNC 30823) DATE: 21/09/17 11:55:37 GMT FROM: Youdong HU at IAA-CSIC <huyoudong072(a)hotmail.com> Y.-D. Hu, T.-R. Sun, E. Fernandez-Garcia, A. J. Castro-Tirado, R. Sanchez-Ramirez and M.D. Caballero-Garcia (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar and I. Carrasco (UMA), I. H. Park (SKKU) on behalf of a larger collaboration, report: The 60cm BOOTES-5/JGT robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) automatically responded in 13 s to the Swift trigger for GRB 210912A (Troja et al., GCNC 30820). In the co-added clear image (30 x 1 s), we find an uncataloged optical source at (J2000) coordinates RA: 8:39:34.30, DEC:+79:13:17.5, which is located at the edge of the XRT error box (Troja et al., GCNC 30820) and for which we measure R = 18.5 mag. We propose this source to be the GRB 210912A optical afterglow, pending confirmation of its variability. Further observations are ongoing. We thank the staff at San Pedro Martir for their support. In the GCNC 30823, we have a typo of the GRB name in the text and it was corrected now. We apologize for the possible confusion and inconvenience.

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