March 2022 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 29706] Fermi Gamma-ray Burst Monitor trigger 220331776/670444627 is not a GRB
by GCN Circulars 01 Apr '22

01 Apr '22

TITLE: GCN CIRCULAR NUMBER: 31809 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 220331776/670444627 is not a GRB DATE: 22/03/31 19:28:51 GMT FROM: Rachel Hamburg at UAH <rkh0007(a)uah.edu> R. Hamburg (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: “The Fermi Gamma-ray Burst Monitor (GBM) trigger 220331776/670444627 at 18:37:02.27 UT on 31 March 2022, tentatively classified as a GRB (GCN 31808), is in fact not due to a GRB. This trigger is due to a solar flare.”

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[vsnet-grb-info 29705] GRB 220331A: Fermi GBM Final Real-time Localization
by GCN Circulars 01 Apr '22

01 Apr '22

TITLE: GCN CIRCULAR NUMBER: 31808 SUBJECT: GRB 220331A: Fermi GBM Final Real-time Localization DATE: 22/03/31 18:47:19 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 18:37:02 UT on 31 Mar 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220331A (trigger 670444627.268388 / 220331776). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 12.8, Dec = 2.9 (J2000 degrees, equivalent to J2000 00h 51m, 2d 53'), with a statistical uncertainty of 4.1 degrees. The angle from the Fermi LAT boresight is 58.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220331776/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220331776/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220331776/…

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[vsnet-grb-info 29704] Fermi GRB 220330A: Global MASTER-Net observations report
by GCN Circulars 30 Mar '22

30 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31807 SUBJECT: Fermi GRB 220330A: Global MASTER-Net observations report DATE: 22/03/30 13:30:29 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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 (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-OAGH robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 220330A ( Fermi GBM team, GCN 31806) errorbox 37 sec after notice time and 66 sec after trigger time at 2022-03-30 12:29:15 UT, with upper limit up to 17.1 mag. Observations started at twilight. The observations began at zenith distance = 47 deg. The sun altitude is -9.6 deg. MASTER-Amur robotic telescope located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 220330A errorbox 51 sec after notice time and 80 sec after trigger time at 2022-03-30 12:29:29 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 67 deg. The sun altitude is -23.1 deg. The galactic latitude b = 8 deg., longitude l = 103 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1927341 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 71 | 2022-03-30 12:29:15 | MASTER-OAGH | (21h 20m 30.17s , +62d 49m 52.5s) | C | 10 | 16.9 | 91 | 2022-03-30 12:29:29 | MASTER-Amur | (21h 30m 59.44s , +63d 07m 26.5s) | C | 20 | 16.9 | 107 | 2022-03-30 12:29:46 | MASTER-OAGH | (21h 21m 26.31s , +62d 20m 46.1s) | C | 20 | 17.0 | 107 | 2022-03-30 12:29:46 | MASTER-OAGH | (21h 20m 25.32s , +62d 49m 09.0s) | C | 20 | 17.1 | 130 | 2022-03-30 12:30:09 | MASTER-Amur | (21h 30m 52.87s , +63d 06m 20.1s) | C | 20 | 16.9 | 148 | 2022-03-30 12:30:27 | MASTER-OAGH | (21h 20m 25.46s , +62d 50m 10.3s) | C | 20 | 16.8 | 148 | 2022-03-30 12:30:27 | MASTER-OAGH | (21h 21m 26.38s , +62d 21m 47.1s) | C | 20 | 16.9 | 175 | 2022-03-30 12:30:49 | MASTER-Amur | (21h 30m 58.51s , +63d 06m 22.2s) | C | 30 | 17.2 | 194 | 2022-03-30 12:31:08 | MASTER-OAGH | (21h 20m 30.63s , +62d 49m 11.9s) | C | 30 | 16.8 | 194 | 2022-03-30 12:31:08 | MASTER-OAGH | (21h 21m 31.38s , +62d 20m 48.4s) | C | 30 | 16.8 | 230 | 2022-03-30 12:31:38 | MASTER-Amur | (21h 30m 55.74s , +63d 08m 05.0s) | C | 40 | 17.3 | 250 | 2022-03-30 12:31:59 | MASTER-OAGH | (21h 20m 25.76s , +62d 48m 12.7s) | C | 40 | 16.8 | 250 | 2022-03-30 12:31:59 | MASTER-OAGH | (21h 21m 26.33s , +62d 19m 48.6s) | C | 40 | 16.7 | 294 | 2022-03-30 12:32:38 | MASTER-Amur | (21h 30m 55.02s , +63d 06m 11.5s) | C | 50 | 17.4 | 321 | 2022-03-30 12:33:00 | MASTER-OAGH | (21h 20m 31.69s , +62d 48m 40.7s) | C | 60 | 16.6 | 321 | 2022-03-30 12:33:00 | MASTER-OAGH | (21h 21m 32.12s , +62d 20m 15.8s) | C | 60 | 16.7 | 373 | 2022-03-30 12:33:47 | MASTER-Amur | (21h 30m 57.89s , +63d 07m 45.6s) | C | 70 | 17.5 | 407 | 2022-03-30 12:34:21 | MASTER-OAGH | (21h 20m 28.95s , +62d 50m 12.7s) | C | 70 | 16.5 | 407 | 2022-03-30 12:34:21 | MASTER-OAGH | (21h 21m 29.28s , +62d 21m 47.0s) | C | 70 | 16.5 | 461 | 2022-03-30 12:35:20 | MASTER-Amur | (21h 05m 02.96s , +64d 18m 58.6s) | C | 60 | 17.9 | 494 | 2022-03-30 12:35:52 | MASTER-OAGH | (21h 22m 29.00s , +62d 02m 47.9s) | C | 60 | 16.0 | 494 | 2022-03-30 12:35:52 | MASTER-OAGH | (21h 23m 27.73s , +61d 34m 24.7s) | C | 60 | 16.1 | 541 | 2022-03-30 12:36:40 | MASTER-Amur | (21h 23m 22.59s , +64d 18m 08.6s) | C | 60 | 17.7 | 651 | 2022-03-30 12:38:00 | MASTER-Amur | (21h 42m 47.22s , +63d 23m 04.0s) | C | 120 | 17.6 | 801 | 2022-03-30 12:40:19 | MASTER-Amur | (21h 42m 52.69s , +63d 23m 29.4s) | C | 140 | 17.6 | 980 | 2022-03-30 12:42:59 | MASTER-Amur | (21h 42m 49.87s , +63d 24m 48.3s) | C | 180 | 17.9 | 1180 | 2022-03-30 12:46:18 | MASTER-Amur | (21h 42m 49.23s , +63d 23m 25.5s) | C | 180 | 17.9 | 1319 | 2022-03-30 12:49:38 | MASTER-Amur | (21h 39m 38.66s , +64d 18m 08.5s) | C | 60 | 17.6 | 1614 | 2022-03-30 12:54:33 | MASTER-Amur | (22h 06m 40.37s , +63d 37m 11.9s) | C | 60 | 17.7 | 1695 | 2022-03-30 12:55:54 | MASTER-Amur | (21h 05m 10.51s , +64d 17m 49.2s) | C | 60 | 17.7 | 1775 | 2022-03-30 12:57:14 | MASTER-Amur | (21h 23m 30.29s , +64d 18m 09.6s) | C | 60 | 17.8 | 1855 | 2022-03-30 12:58:33 | MASTER-Amur | (21h 23m 42.97s , +66d 11m 54.8s) | C | 60 | 17.8 | 1934 | 2022-03-30 12:59:53 | MASTER-Amur | (21h 43m 20.23s , +66d 13m 51.1s) | C | 60 | 17.5 | 2019 | 2022-03-30 13:01:18 | MASTER-Amur | (21h 39m 36.72s , +60d 31m 51.9s) | C | 60 | 17.4 | 2098 | 2022-03-30 13:02:37 | MASTER-Amur | (21h 55m 45.97s , +60d 30m 58.6s) | C | 60 | 17.2 | 2186 | 2022-03-30 13:04:05 | MASTER-Amur | (21h 09m 09.99s , +60d 29m 32.5s) | C | 60 | 17.5 | 2266 | 2022-03-30 13:05:25 | MASTER-Amur | (21h 25m 10.42s , +60d 31m 07.0s) | C | 60 | 17.3 | 2345 | 2022-03-30 13:06:44 | MASTER-Amur | (21h 39m 48.03s , +64d 17m 49.7s) | C | 60 | 17.6 | 2425 | 2022-03-30 13:08:04 | MASTER-Amur | (21h 55m 09.06s , +62d 24m 47.8s) | C | 60 | 17.3 | 2710 | 2022-03-30 13:12:48 | MASTER-Amur | (22h 20m 25.56s , +61d 43m 08.3s) | C | 60 | 17.3 | 2791 | 2022-03-30 13:14:10 | MASTER-Amur | (21h 57m 59.57s , +64d 18m 09.6s) | C | 60 | 17.4 | 2871 | 2022-03-30 13:15:30 | MASTER-Amur | (21h 05m 15.11s , +64d 17m 22.6s) | C | 60 | 17.8 | 2951 | 2022-03-30 13:16:50 | MASTER-Amur | (21h 23m 24.84s , +64d 19m 03.6s) | C | 60 | 17.7 | 3031 | 2022-03-30 13:18:10 | MASTER-Amur | (21h 23m 40.35s , +66d 11m 48.7s) | C | 60 | 17.8 | 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 29703] GRB 220330A: Fermi GBM Final Real-time Localization
by GCN Circulars 30 Mar '22

30 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31806 SUBJECT: GRB 220330A: Fermi GBM Final Real-time Localization DATE: 22/03/30 12:38:33 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 12:28:09 UT on 30 Mar 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220330A (trigger 670336094.273364 / 220330520). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 324.1, Dec = 63.1 (J2000 degrees, equivalent to J2000 21h 36m, 63d 06'), with a statistical uncertainty of 3.8 degrees. The angle from the Fermi LAT boresight is 28.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220330520/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220330520/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220330520/…

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[vsnet-grb-info 29702] ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
by GCN Circulars 30 Mar '22

30 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31805 SUBJECT: ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations DATE: 22/03/29 19:04:43 GMT FROM: Rahul Gupta at ARIES, India <rahulbhu.c157(a)gmail.com> Dimple, Rahul Gupta, Ankur Ghosh, Naveen Dukiya, Amit Kumar, Amit Ror, Amar Aryan, Kiran Wani, Kuntal Misra, and S. B. Pandey (ARIES) report: We observed the fast and red optical transient ZTF22aaajecp/AT2022cmc discovered with the Zwicky Transient Facility (Andreoni et al., GCN 31590) using 1.3m Devasthal Fast Optical Telescope (DFOT) located at Devasthal observatory of Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were carried out at multiple epochs. Here, we report our last night's observations, which started on 22-03 28 at 19:32:05 UT~ 45.4 days after the first detection by the ZTF. We have taken multiple frames having an exposure time of 120 sec in the R filter. We stacked the images after the alignment. We detected ZTF22aaajecp/AT2022cmc (Andreoni et al., GCN 31590; Pankov et al., GCNs 31593, 31625, 31652, 31798; Perley, GCN 31594; Kumar et al., GCN 31597; Lipunov et al., GCN 31600; Tanvir et al., GCN 31602; Lundquist et al., GCN 31612; Kann et al., GCN 31626; Yao et al., GCN 31641; Freeburn et al., GCN 31647; and Cenko et al., GCN 31729) in our stacked image. The estimated preliminary magnitude is following: Date Start_UT T_start-T0 (days) Filter Exp time (sec) magnitude ============================================================== 2022-03-28 19:32 ~45.4 R 120 sec*60 22.04 +/- 0.10 The magnitude is not corrected for the Galactic extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the USNO-B1.0 catalog. This circular may be cited.

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[vsnet-grb-info 29701] GRB 220325A: GRANDMA observations
by GCN Circulars 30 Mar '22

30 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31804 SUBJECT: GRB 220325A: GRANDMA observations DATE: 22/03/29 18:08:27 GMT FROM: Sarah Antier at OCA <sarah.antier(a)oca.eu> C. Andrade, M. Coughlin (UNM), K. Noysena (NARIT), W. Kiendrebeogo (UJS), I. Tosta e Melo (INFN-LNS), X. F. Wang (TSU/BJP), F. Navarete (NOIRLab/SOAR) J. Zhu (BJP), L. Wang (XAO), A. Iskandar (XAO), X. Zeng (XAO), L. Abe, Ph. Bendjoya, J.-P. Rivet (Lagrange/OCA), D. Vernet (Galilee/OCA), S. Antier, A. de Ugarte Postigo (Artemis/OCA), A. M. Fouad, A. Taky, A. Shokry, I. Elhousiny, A. Eid, M. Farouk (NRIAG), P.A. Duverne (IJCLAB) report on behalf of the GRANDMA collaboration: The GRANDMA telescope network responded to the alert of GRB 220325A (Palmer et al. GCN 31787). The first observations started 4.28 h after the BAT trigger time. No new object was detected within the XRT enhanced error region (Evans et al. GCN 31794). In the following table we report the preliminary photometry of our observations. Upper limits are reported at the 3-sigma limit, in the AB system. T-T0 (hr)| MJD | Observatory| Exposure| Filter | Upp.Lim. (AB) _____________________________________________________________________ 04.28 |59663.89971| SNOVA | 9x300s | Bessel R | 20.1 04.44 |59663.90475| NOWT | 11x180s | Bessel R | 19.7 08.11 |59664.05765| KAO | 22x50s | SDSS i | 21.2 10.14 |59664.14304| C2PU | 16x240s | SDSS r | 20.8 These limits are consistent with the non-detections previously reported (Gupta et al. GCN 31793, Strausbaugh et al. GCN 31795, Nicuesa Guelbenzu et al. GCN 31797). The photometry of NOWT and SNOVA was performed using field stars from the APASS catalog. The KAO and C2PU image have been processed using field stars from the PanSTARRS-DR1 catalog and with the MUPHOTEN pipeline (Duverne et al. 2021). The magnitudes are not corrected for the Galactic extinction in the direction of the burst. GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).

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[vsnet-grb-info 29700] GRB 220320A: Detection by VZLUSAT-2
by GCN Circulars 29 Mar '22

29 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31803 SUBJECT: GRB 220320A: Detection by VZLUSAT-2 DATE: 22/03/29 04:06:06 GMT FROM: Jakub Ripa at Masaryk University <ripa.jakub(a)mail.muni.cz> J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), M. Ohno (Eotvos U./Hiroshima U.), N. Werner (Masaryk U.), L. Meszaros (Konkoly Observatory), H. Takahashi (Hiroshima U.), B. Csak (Konkoly Observatory), M. Topinka, F. Munz, F. Hroch (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration. The bright, long-duration GRB 220320A (AstroSat-CZTI detection: Gopalakrishnan et al., GCN Circ. 31779; localized by IPN: Kozyrev et al. GCN Circ. 31783 and detected also by Fermi/GBM trigger 669443999, CALET/CGBM trigger 1331786356, Konus-Wind, INTEGRAL/SPI-ACS at about 04:39:54 UT) was also detected by one of the two GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/). This is the first time that a GRB was observed by the VZLUSAT-2 3U CubeSat. The data acquisition was performed by GRB detector unit no. 1 (the unit no. 0 was turned off). The detector was performing a several hours long background monitoring survey with 15 s temporal resolution, which is not optimal for GRB search. Much finer resolution is planned for the nominal operation. The 46 sigma detection significance was confirmed at around 04:39:55 UTC. The light curve obtained by VZLUSAT-2 is available here: https://vzlusat2.konkoly.hu/static/share/GRB220320A_GCN_VZLUSAT_2.pdf GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSats constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.

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[vsnet-grb-info 29699] Konus-Wind observation of GRB 220320A
by GCN Circulars 29 Mar '22

29 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31802 SUBJECT: Konus-Wind observation of GRB 220320A DATE: 22/03/28 16:58:44 GMT FROM: Anastasia Tsvetkova at Ioffe Institute <tsvetkova(a)mail.ioffe.ru> A. Tsvetkova, D. Frederiks, D. Svinkin, M. Ulanov, A. Lysenko, A. Ridnaia and T. Cline on behalf of the Konus-Wind team, report: The long-duration, bright GRB 220320A (AstroSat CZTI detection: Gopalakrishnan et al., GCN 31779; IPN triangulation: Kozyrev et al., GCN 31783) triggered Konus-Wind at T0=16796.141 s UT (04:39:56.141). The burst light curve shows a multi-peaked structure which starts at ~T0-18.8 s and has a total duration of~52.8 s The emission is seen up to ~20 MeV. As observed by Konus-Wind, the burst had a fluence of 6.05(-0.50,+0.52)x10^-5 erg/cm2, and a 64-ms peak energy flux, measured from T0+4.048 s, of 2.50(-0.34,+0.34)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+20.480 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.84(-0.09,+0.10), the high energy photon index beta = -2.27(-0.15,+0.11), the peak energy Ep = 224(-21,+24) keV, chi2 = 100/97 dof. The spectrum near the peak count rate (measured from T0 to T0+4.352 s) is best fit in the 20 keV - 20 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.43(-0.11,+0.12), the high energy photon index beta = -2.31(-0.17,+0.13), the peak energy Ep = 311(-29,+33) keV, chi2 = 67/86 dof. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB220320_T16796/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.

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[vsnet-grb-info 29698] GRB 220325A: Swift/UVOT Upper Limits
by GCN Circulars 29 Mar '22

29 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31801 SUBJECT: GRB 220325A: Swift/UVOT Upper Limits DATE: 22/03/28 16:02:38 GMT FROM: Paul Kuin at MSSL <npkuin(a)gmail.com> N. P. M. Kuin (UCL-MSSL) and M. Ferro (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 220325A 114 s after the BAT trigger (Ferro et al., GCN Circ. 31787). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 31790) 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 114 264 147 >20.8 u_FC 326 576 246 >20.1 white 114 5035 488 >21.0 v 657 1234 78 >18.7 b 582 4893 255 >20.1 u 326 4688 481 >20.3 w1 707 726 19 >17.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.915 in the direction of the burst (Schlegel et al. 1998).

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[vsnet-grb-info 29697] GRB 211024B: Host galaxy redshift from X-shooter/VLT
by GCN Circulars 28 Mar '22

28 Mar '22

TITLE: GCN CIRCULAR NUMBER: 31800 SUBJECT: GRB 211024B: Host galaxy redshift from X-shooter/VLT DATE: 22/03/28 15:57:26 GMT FROM: Antonio de Ugarte Postigo at OCA <deugarte(a)oca.eu> A. de Ugarte Postigo (Artemis/OCA), B. Schneider (CEA Paris-Saclay), D. B. Malesani (Radboud Univ. and DAWN/NBI), D. A. Kann (IAA-CSIC) report on behalf of the Stargate collaboration: We observed the location of the ultra-long GRB 211024B (Gropp et al. GCN 30980, Zhu et al. GCN 30984) using the X-shooter spectrograph mounted on the UT3 of ESO’s Very Large Telescope. The observation was performed on 27 March 2022 (153 days after the GRB) and consisted of 4x1200 s in the UVB and VIS arms and 8x600 s in the NIR arm. We used the JH-slit that blocks part of the K-band and in return increases the efficiency of the J and H bands, resulting in a wavelength coverage between 3000 to 21000 AA. In a preliminary reduction we detect two weak emission lines that we identify as [OII]3727 and [OIII] 5008, as well as a marginal detection of [OII]4960 at a common redshift of z=1.1137+/-0.0002. The other line of the OII doublet, [OII]3729 is affected by a sky line and is consequently not detected. H-alpha falls within a telluric absorption and H-beta in a spectral region of low sensitivity, both resulting in non detections. Given the spatial coincidence of these emissions with the afterglow, we identify the underlying object as the host galaxy and propose this as the redshift of the GRB. We acknowledge expert support from the ESO staff in Paranal, in particular Cedric Ledoux and Michael Abdul-Masih.

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