February 2023 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 31187] GRB 230228A: Mondy optical upper limit
by GCN Circulars 28 Feb '23

28 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33383 SUBJECT: GRB 230228A: Mondy optical upper limit DATE: 23/02/28 19:12:56 GMT FROM: XXXX at IKI <alex(a)cgrsmx.iki.rssi.ru> S. Belkin (IKI, HSE), E. Klunko (ISTP), A. Pozanenko (IKI), N. Pankov (HSE) report on behalf of GRB IKI FuN: We observed the field of GRB 230228A (Dichiara et al., GCN 33378) with AZT-33 telescope of Mondy observatory starting on Feb. 28 (UT) 12:46:56. We do not detect any optical counterpart within the enhanced Swift/XRT error box (Beardmore et al., GCN 33382). Preliminary photometry of the field is following Date UT start t-T0 Filter Exp. OT Err UL(3sigma) 2023-02-28 12:46:56 0.31053 R 30*120 n/d n/d 21.1 The photometry is based on the nearby USNO-B1.0 stars R2 RA DEC R2 01:13:35.3661600 +44:26:54.711600 15.50 01:13:18.4240800 +44:28:30.280800 16.70 The upper limit is not contradict observations reported earlier (Dichiara et al., GCN 33378; Lim et al., GCN 33380; Lu et al., GCN 33381).

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[vsnet-grb-info 31186] GRB 230228A: Enhanced Swift-XRT position
by GCN Circulars 28 Feb '23

28 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33382 SUBJECT: GRB 230228A: Enhanced Swift-XRT position DATE: 23/02/28 17:09:14 GMT FROM: Phil Evans at U of Leicester <pae9(a)leicester.ac.uk> A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 2720 s of XRT Photon Counting mode data and 3 UVOT images for GRB 230228A, 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 = 18.37812, +44.48293 which is equivalent to: RA (J2000): 01h 13m 30.75s Dec (J2000): +44d 28' 58.5" with an uncertainty of 2.1 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 31185] GRB 230228A: Nanshan/NEXT optical upper limit
by GCN Circulars 28 Feb '23

28 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33381 SUBJECT: GRB 230228A: Nanshan/NEXT optical upper limit DATE: 23/02/28 16:50:31 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> T.H. Lu, S.Q. Jiang, S.Y. Fu, X. Liu (NAOC), Z.P. Zhu (NAOC, HUST), D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of GRB 230228A detected by Swift (Dichiara et al., GCN 33378) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 12x200 s frames in the Sloan r-band and 12x200 s frames in the Sloan z-band, starting at 14:37:32 UT on 2023-02-28 (i.e., 8.77 hr after the BAT trigger). No optical source is detected in our stacked images at the enhanced XRT position (Evans, GCN 33379), and preliminary photometric results are as follows: T_mid-T0 (hr) Filter Upper limit(3-sigma) 9.86 r >20.6 9.14 z >19.5 calibrated with the nearby PanSTARRS field and not corrected for Galactic extinction.

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[vsnet-grb-info 31184] GRB 230228A: Miryang Arirang Astronomical Observatory (MAAO) 0.7-m telescope optical upper limit
by GCN Circulars 28 Feb '23

28 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33380 SUBJECT: GRB 230228A: Miryang Arirang Astronomical Observatory (MAAO) 0.7-m telescope optical upper limit DATE: 23/02/28 13:33:13 GMT FROM: Gu Lim at Seoul National U <lim9gu(a)gmail.com> Gu Lim (PNU), Donghyun Kim (PNU), Dohyeong Kim (PNU), Myungshin Im (SNU ARC/SNU), Gregory S.H. Paek (SNU ARC/SNU), Keun-Hong Park (MAAO), and Seonghun Lim (MAAO) on behalf of GECKO collaboration We searched for the optical counterpart of a possible short burst GRB 230228A (Dichiara et al. GCN #33378) with the 0.7-m telescope at Miryang Arirang Astronomical Observatory (MAAO), located at Miryang, Republic of Korea. We observed the center of Swift-XRT localization (RA, Dec = 01:13:30.73, +44:28:58.4; Evans et al. GCN #33379) +4.09 hours after report, but could not find any possible transient within the field of view (28.2' x 28.2'). We performed flux calibration with the PS1 catalog and used the AB magnitude system. Each depth means 3 and 5 sigma upper limit for a point source detection. The magnitudes are not corrected for galactic extinction. object exposures date-obs (UT) MJD band Depth(3σ) Depth(5 σ) FWHM(") ========================================================================================= GRB230228A 60sx8 2023-02-28T09:56:11 60003.414 V <18.77 <18.21 2.8 Gravitational wave Electromagnetic wave Counterpart Korean Observatory (GECKO) is a network of 10+ 0.5m to 1m class telescopes over the world. ᐧ

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[vsnet-grb-info 31183] GRB 230228A: Prompt enhanced Swift-XRT position
by GCN Circulars 28 Feb '23

28 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33379 SUBJECT: GRB 230228A: Prompt enhanced Swift-XRT position DATE: 23/02/28 06:35:05 GMT FROM: Phil Evans at U of Leicester <pae9(a)leicester.ac.uk> P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 230228A, we find an enhanced XRT position of the afterglow: RA, Dec: 18.37804, 44.48289 which is equivalent to: RA (J2000) = 01 13 30.73 Dec (J2000) = +44 28 58.4 with an uncertainty of 1.9 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/1156572. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team.

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[vsnet-grb-info 31182] GRB 230228A: Swift detection of a possibly short burst
by GCN Circulars 28 Feb '23

28 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33378 SUBJECT: GRB 230228A: Swift detection of a possibly short burst DATE: 23/02/28 06:03:29 GMT FROM: David Palmer at LANL <palmer(a)lanl.gov> S. Dichiara (PSU), J.D. Gropp (PSU), D. M. Palmer (LANL) and T. M. Parsotan (GSFC/UMBC/CRESSTII) report on behalf of the Neil Gehrels Swift Observatory Team: At 05:50:50 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 230228A (trigger=1156572). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 18.403, +44.489 which is RA(J2000) = 01h 13m 37s Dec(J2000) = +44d 29' 19" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single symmetrical peak structure with a duration of about 1.5 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 05:52:49.2 UT, 119.0 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 18.37776, 44.48321 which is equivalent to: RA(J2000) = 01h 13m 30.66s Dec(J2000) = +44d 28' 59.6" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 68 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 9.72 x 10^20 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 122 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 19.6 mag. 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 0.085. Burst Advocate for this burst is S. Dichiara (simonedichiara55 AT gmail.com). 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 31181] Fermi GRB 230227A: Global MASTER-Net observations report
by GCN Circulars 27 Feb '23

27 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33377 SUBJECT: Fermi GRB 230227A: Global MASTER-Net observations report DATE: 23/02/27 20:45:23 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-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 230227A ( Fermi GBM team, GCN 33376) errorbox 27935 sec after notice time and 27945 sec after trigger time at 2023-02-27 18:07:48 UT, with upper limit up to 18.0 mag. Observations started at twilight. The observations began at zenith distance = 71 deg. The sun altitude is -11.4 deg. The galactic latitude b = -61 deg., longitude l = 335 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2201434 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 27975 | 2023-02-27 18:07:48 | MASTER-SAAO | (23h 22m 43.55s , -50d 06m 48.8s) | C | 60 | 15.8 | 28055 | 2023-02-27 18:09:07 | MASTER-SAAO | (23h 03m 26.41s , -48d 11m 15.9s) | C | 60 | 14.7 | 28146 | 2023-02-27 18:10:39 | MASTER-SAAO | (23h 15m 26.92s , -48d 13m 00.1s) | C | 60 | 15.7 | 28533 | 2023-02-27 18:17:05 | MASTER-SAAO | (22h 54m 28.18s , -51d 59m 07.3s) | C | 60 | 16.4 | 28612 | 2023-02-27 18:18:25 | MASTER-SAAO | (23h 07m 21.20s , -51d 59m 54.1s) | C | 60 | 17.1 | 28703 | 2023-02-27 18:19:56 | MASTER-SAAO | (23h 19m 03.56s , -51d 59m 04.8s) | C | 60 | 17.4 | 28782 | 2023-02-27 18:21:15 | MASTER-SAAO | (23h 32m 10.32s , -52d 00m 19.3s) | C | 60 | 17.6 | 28956 | 2023-02-27 18:24:09 | MASTER-SAAO | (22h 59m 02.16s , -50d 06m 24.6s) | C | 60 | 17.1 | 29048 | 2023-02-27 18:25:40 | MASTER-SAAO | (23h 04m 37.58s , -53d 52m 45.1s) | C | 60 | 17.5 | 29138 | 2023-02-27 18:27:11 | MASTER-SAAO | (23h 18m 13.09s , -53d 54m 42.5s) | C | 60 | 17.8 | 29223 | 2023-02-27 18:28:36 | MASTER-SAAO | (23h 10m 16.61s , -50d 05m 00.7s) | C | 60 | 17.2 | 29314 | 2023-02-27 18:30:07 | MASTER-SAAO | (23h 22m 39.71s , -50d 05m 57.9s) | C | 60 | 17.9 | 29399 | 2023-02-27 18:31:32 | MASTER-SAAO | (23h 03m 25.78s , -48d 10m 31.1s) | C | 60 | 17.0 | 29489 | 2023-02-27 18:33:01 | MASTER-SAAO | (23h 15m 32.95s , -48d 11m 45.1s) | C | 60 | 17.5 | 29570 | 2023-02-27 18:34:23 | MASTER-SAAO | (22h 54m 24.11s , -52d 00m 20.0s) | C | 60 | 17.1 | 29659 | 2023-02-27 18:35:52 | MASTER-SAAO | (23h 07m 28.96s , -52d 00m 30.7s) | C | 60 | 17.9 | 29749 | 2023-02-27 18:37:22 | MASTER-SAAO | (23h 19m 08.93s , -51d 58m 50.7s) | C | 60 | 17.9 | 29829 | 2023-02-27 18:38:42 | MASTER-SAAO | (23h 32m 09.06s , -52d 00m 48.4s) | C | 60 | 18.0 | 29926 | 2023-02-27 18:40:18 | MASTER-SAAO | (22h 58m 57.37s , -50d 05m 19.4s) | C | 60 | 17.6 | 30005 | 2023-02-27 18:41:38 | MASTER-SAAO | (23h 04m 36.55s , -53d 52m 26.0s) | C | 60 | 18.0 | 30096 | 2023-02-27 18:43:09 | MASTER-SAAO | (23h 18m 17.75s , -53d 53m 39.5s) | C | 60 | 18.0 | 30175 | 2023-02-27 18:44:28 | MASTER-SAAO | (23h 26m 21.92s , -48d 12m 46.9s) | C | 60 | 17.9 | 31810 | 2023-02-27 19:11:42 | MASTER-SAAO | (23h 35m 15.88s , -50d 04m 17.8s) | C | 60 | 17.8 | 31810 | 2023-02-27 19:11:42 | MASTER-SAAO | (23h 33m 34.02s , -50d 04m 42.6s) | C | 60 | 17.2 | 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 31180] GRB 230227A: Fermi GBM Final Real-time Localization
by GCN Circulars 27 Feb '23

27 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33376 SUBJECT: GRB 230227A: Fermi GBM Final Real-time Localization DATE: 23/02/27 10:32:34 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 10:22:03 UT on 27 Feb 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230227A (trigger 699186128.22906 / 230227432). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 348.0, Dec = -50.4 (J2000 degrees, equivalent to J2000 23h 11m, -50d 23'), with a statistical uncertainty of 1.8 degrees. The angle from the Fermi LAT boresight is 120.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230227432/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230227432/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230227432/…

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[vsnet-grb-info 31179] Fermi trigger No 699029364: Global MASTER-Net observations report
by GCN Circulars 25 Feb '23

25 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33375 SUBJECT: Fermi trigger No 699029364: Global MASTER-Net observations report DATE: 23/02/25 19:15:29 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-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 GRB230225.62 (trigger No 699029364,03h 04m 02.40s , -31d 10m 48.0s, R=5.24) errorbox 11469 sec after notice time and 11502 sec after trigger time at 2023-02-25 18:01:02 UT, with upper limit up to 19.0 mag. Observations started at twilight. The observations began at zenith distance = 35 deg. The sun altitude is -9.5 deg. The galactic latitude b = -60 deg., longitude l = 229 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2201226 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 11533 | 2023-02-25 18:01:02 | MASTER-SAAO | (02h 57m 35.57s , -29d 15m 23.0s) | C | 60 | 15.7 | 11533 | 2023-02-25 18:01:02 | MASTER-SAAO | (02h 58m 35.42s , -29d 15m 46.5s) | C | 60 | 15.5 | 11618 | 2023-02-25 18:02:27 | MASTER-SAAO | (03h 09m 28.40s , -31d 11m 25.3s) | C | 60 | 16.3 | 11618 | 2023-02-25 18:02:27 | MASTER-SAAO | (03h 10m 29.73s , -31d 11m 48.6s) | C | 60 | 16.2 | 11709 | 2023-02-25 18:03:58 | MASTER-SAAO | (03h 18m 54.64s , -31d 11m 21.2s) | C | 60 | 16.7 | 11709 | 2023-02-25 18:03:58 | MASTER-SAAO | (03h 19m 56.19s , -31d 11m 44.5s) | C | 60 | 16.6 | 11789 | 2023-02-25 18:05:18 | MASTER-SAAO | (02h 59m 20.84s , -34d 59m 04.7s) | C | 60 | 16.5 | 11789 | 2023-02-25 18:05:18 | MASTER-SAAO | (03h 00m 25.07s , -34d 59m 27.7s) | C | 60 | 16.6 | 11880 | 2023-02-25 18:06:49 | MASTER-SAAO | (03h 09m 08.80s , -34d 57m 42.0s) | C | 60 | 16.9 | 11880 | 2023-02-25 18:06:49 | MASTER-SAAO | (03h 10m 13.25s , -34d 58m 04.9s) | C | 60 | 16.7 | 11959 | 2023-02-25 18:08:08 | MASTER-SAAO | (02h 37m 09.56s , -33d 02m 54.2s) | C | 60 | 16.4 | 11959 | 2023-02-25 18:08:08 | MASTER-SAAO | (02h 38m 12.24s , -33d 03m 18.1s) | C | 60 | 16.4 | 12051 | 2023-02-25 18:09:40 | MASTER-SAAO | (02h 46m 47.23s , -33d 03m 57.3s) | C | 60 | 16.9 | 12051 | 2023-02-25 18:09:40 | MASTER-SAAO | (02h 47m 50.15s , -33d 04m 21.5s) | C | 60 | 16.9 | 12142 | 2023-02-25 18:11:11 | MASTER-SAAO | (02h 51m 39.68s , -31d 10m 58.5s) | C | 60 | 17.0 | 12142 | 2023-02-25 18:11:11 | MASTER-SAAO | (02h 52m 41.46s , -31d 11m 22.9s) | C | 60 | 17.0 | 12222 | 2023-02-25 18:12:31 | MASTER-SAAO | (03h 01m 08.71s , -31d 10m 43.6s) | C | 60 | 17.3 | 12222 | 2023-02-25 18:12:31 | MASTER-SAAO | (03h 02m 10.69s , -31d 11m 07.6s) | C | 60 | 17.4 | 12313 | 2023-02-25 18:14:02 | MASTER-SAAO | (02h 55m 20.83s , -33d 02m 56.2s) | C | 60 | 17.5 | 12313 | 2023-02-25 18:14:02 | MASTER-SAAO | (02h 56m 24.17s , -33d 03m 20.2s) | C | 60 | 17.5 | 12392 | 2023-02-25 18:15:21 | MASTER-SAAO | (03h 04m 54.08s , -33d 04m 30.6s) | C | 60 | 17.6 | 12392 | 2023-02-25 18:15:21 | MASTER-SAAO | (03h 05m 57.63s , -33d 04m 54.3s) | C | 60 | 17.8 | 12483 | 2023-02-25 18:16:52 | MASTER-SAAO | (02h 48m 27.17s , -29d 14m 52.1s) | C | 60 | 17.4 | 12483 | 2023-02-25 18:16:52 | MASTER-SAAO | (02h 49m 28.00s , -29d 15m 16.9s) | C | 60 | 17.6 | 12563 | 2023-02-25 18:18:12 | MASTER-SAAO | (02h 57m 32.18s , -29d 15m 49.5s) | C | 60 | 17.7 | 12563 | 2023-02-25 18:18:12 | MASTER-SAAO | (02h 58m 33.18s , -29d 16m 14.2s) | C | 60 | 18.0 | 12654 | 2023-02-25 18:19:43 | MASTER-SAAO | (03h 09m 27.47s , -31d 08m 51.3s) | C | 60 | 17.9 | 12654 | 2023-02-25 18:19:43 | MASTER-SAAO | (03h 10m 29.91s , -31d 09m 16.0s) | C | 60 | 18.2 | 12744 | 2023-02-25 18:21:13 | MASTER-SAAO | (03h 18m 53.75s , -31d 09m 53.0s) | C | 60 | 18.5 | 12744 | 2023-02-25 18:21:13 | MASTER-SAAO | (03h 19m 56.39s , -31d 10m 17.6s) | C | 60 | 18.6 | 12824 | 2023-02-25 18:22:33 | MASTER-SAAO | (02h 59m 16.26s , -34d 58m 39.0s) | C | 60 | 18.2 | 12824 | 2023-02-25 18:22:33 | MASTER-SAAO | (03h 00m 21.64s , -34d 59m 03.4s) | C | 60 | 18.4 | 12915 | 2023-02-25 18:24:04 | MASTER-SAAO | (03h 09m 08.05s , -34d 58m 37.9s) | C | 60 | 18.4 | 12915 | 2023-02-25 18:24:04 | MASTER-SAAO | (03h 10m 13.58s , -34d 59m 02.0s) | C | 60 | 18.7 | 12994 | 2023-02-25 18:25:23 | MASTER-SAAO | (02h 37m 09.43s , -33d 02m 48.0s) | C | 60 | 18.0 | 12994 | 2023-02-25 18:25:23 | MASTER-SAAO | (02h 38m 13.07s , -33d 03m 13.2s) | C | 60 | 18.1 | 13085 | 2023-02-25 18:26:54 | MASTER-SAAO | (02h 46m 43.02s , -33d 04m 16.8s) | C | 60 | 18.1 | 13085 | 2023-02-25 18:26:54 | MASTER-SAAO | (02h 47m 46.87s , -33d 04m 41.7s) | C | 60 | 18.5 | 13165 | 2023-02-25 18:28:14 | MASTER-SAAO | (02h 51m 42.99s , -31d 08m 40.7s) | C | 60 | 18.1 | 13165 | 2023-02-25 18:28:14 | MASTER-SAAO | (02h 52m 45.59s , -31d 09m 06.1s) | C | 60 | 18.3 | 13256 | 2023-02-25 18:29:45 | MASTER-SAAO | (03h 01m 00.34s , -31d 09m 27.5s) | C | 60 | 18.4 | 13256 | 2023-02-25 18:29:45 | MASTER-SAAO | (03h 02m 03.10s , -31d 09m 52.6s) | C | 60 | 18.6 | 13346 | 2023-02-25 18:31:15 | MASTER-SAAO | (02h 55m 14.88s , -33d 02m 19.9s) | C | 60 | 18.4 | 13346 | 2023-02-25 18:31:15 | MASTER-SAAO | (02h 56m 18.94s , -33d 02m 45.4s) | C | 60 | 18.7 | 13426 | 2023-02-25 18:32:35 | MASTER-SAAO | (03h 04m 56.03s , -33d 03m 22.7s) | C | 60 | 18.5 | 13426 | 2023-02-25 18:32:35 | MASTER-SAAO | (03h 06m 00.27s , -33d 03m 47.8s) | C | 60 | 18.8 | 13517 | 2023-02-25 18:34:06 | MASTER-SAAO | (02h 48m 18.05s , -29d 16m 11.5s) | C | 60 | 17.8 | 13517 | 2023-02-25 18:34:06 | MASTER-SAAO | (02h 49m 19.49s , -29d 16m 37.7s) | C | 60 | 18.0 | 13596 | 2023-02-25 18:35:25 | MASTER-SAAO | (02h 57m 34.44s , -29d 16m 04.7s) | C | 60 | 18.3 | 13596 | 2023-02-25 18:35:25 | MASTER-SAAO | (02h 58m 36.03s , -29d 16m 30.6s) | C | 60 | 18.6 | 13687 | 2023-02-25 18:36:56 | MASTER-SAAO | (03h 09m 27.37s , -31d 08m 33.2s) | C | 60 | 18.6 | 13687 | 2023-02-25 18:36:56 | MASTER-SAAO | (03h 10m 30.34s , -31d 08m 59.2s) | C | 60 | 18.7 | 13766 | 2023-02-25 18:38:15 | MASTER-SAAO | (03h 18m 49.11s , -31d 10m 00.9s) | C | 60 | 18.7 | 13767 | 2023-02-25 18:38:16 | MASTER-SAAO | (03h 19m 52.23s , -31d 10m 26.6s) | C | 60 | 18.8 | 13857 | 2023-02-25 18:39:46 | MASTER-SAAO | (02h 59m 20.49s , -34d 56m 27.7s) | C | 60 | 18.6 | 13857 | 2023-02-25 18:39:46 | MASTER-SAAO | (03h 00m 26.19s , -34d 56m 53.4s) | C | 60 | 18.8 | 13937 | 2023-02-25 18:41:06 | MASTER-SAAO | (03h 09m 02.09s , -34d 57m 07.1s) | C | 60 | 18.7 | 13937 | 2023-02-25 18:41:06 | MASTER-SAAO | (03h 10m 07.92s , -34d 57m 32.3s) | C | 60 | 19.0 | 14029 | 2023-02-25 18:42:38 | MASTER-SAAO | (02h 37m 03.60s , -33d 01m 45.8s) | C | 60 | 17.7 | 14029 | 2023-02-25 18:42:38 | MASTER-SAAO | (02h 38m 07.49s , -33d 02m 12.2s) | C | 60 | 18.0 | 14120 | 2023-02-25 18:44:09 | MASTER-SAAO | (02h 46m 44.29s , -33d 02m 48.4s) | C | 60 | 18.5 | 14120 | 2023-02-25 18:44:09 | MASTER-SAAO | (02h 47m 48.33s , -33d 03m 14.4s) | C | 60 | 18.6 | 14200 | 2023-02-25 18:45:29 | MASTER-SAAO | (03h 05m 49.75s , -29d 15m 47.4s) | C | 60 | 18.5 | 14200 | 2023-02-25 18:45:29 | MASTER-SAAO | (03h 06m 51.49s , -29d 16m 13.7s) | C | 60 | 18.6 | 14290 | 2023-02-25 18:46:59 | MASTER-SAAO | (03h 14m 58.25s , -29d 14m 29.4s) | C | 60 | 18.5 | 14290 | 2023-02-25 18:46:59 | MASTER-SAAO | (03h 16m 00.10s , -29d 14m 56.0s) | C | 60 | 18.7 | 14370 | 2023-02-25 18:48:19 | MASTER-SAAO | (02h 45m 20.80s , -27d 19m 53.8s) | C | 60 | 18.5 | 14370 | 2023-02-25 18:48:19 | MASTER-SAAO | (02h 46m 21.13s , -27d 20m 21.1s) | C | 60 | 18.6 | 14461 | 2023-02-25 18:49:50 | MASTER-SAAO | (02h 54m 16.44s , -27d 20m 41.7s) | C | 60 | 18.5 | 14461 | 2023-02-25 18:49:50 | MASTER-SAAO | (02h 55m 16.88s , -27d 21m 08.7s) | C | 60 | 18.7 | 14541 | 2023-02-25 18:51:10 | MASTER-SAAO | (03h 13m 29.02s , -33d 02m 49.0s) | C | 60 | 18.7 | 14541 | 2023-02-25 18:51:10 | MASTER-SAAO | (03h 14m 33.43s , -33d 03m 15.4s) | C | 60 | 18.7 | 14632 | 2023-02-25 18:52:41 | MASTER-SAAO | (03h 22m 57.80s , -33d 03m 50.7s) | C | 60 | 18.8 | 14632 | 2023-02-25 18:52:41 | MASTER-SAAO | (03h 24m 02.37s , -33d 04m 16.9s) | C | 60 | 18.9 | 14723 | 2023-02-25 18:54:12 | MASTER-SAAO | (02h 40m 42.08s , -34d 55m 35.0s) | C | 60 | 17.8 | 14723 | 2023-02-25 18:54:12 | MASTER-SAAO | (02h 41m 47.56s , -34d 56m 02.5s) | C | 60 | 17.9 | 15230 | 2023-02-25 19:02:39 | MASTER-SAAO | (02h 50m 24.79s , -34d 56m 14.8s) | C | 60 | 18.5 | 15230 | 2023-02-25 19:02:39 | MASTER-SAAO | (02h 51m 30.83s , -34d 56m 43.2s) | C | 60 | 18.5 | 15321 | 2023-02-25 19:04:10 | MASTER-SAAO | (03h 05m 40.18s , -29d 13m 21.3s) | C | 60 | 18.4 | 15321 | 2023-02-25 19:04:10 | MASTER-SAAO | (03h 06m 42.19s , -29d 13m 49.8s) | C | 60 | 18.4 | 15401 | 2023-02-25 19:05:30 | MASTER-SAAO | (03h 14m 57.85s , -29d 14m 23.8s) | C | 60 | 18.6 | 15401 | 2023-02-25 19:05:30 | MASTER-SAAO | (03h 15m 59.91s , -29d 14m 52.1s) | C | 60 | 18.6 | 15491 | 2023-02-25 19:07:00 | MASTER-SAAO | (02h 45m 11.45s , -27d 21m 01.9s) | C | 60 | 18.5 | 15491 | 2023-02-25 19:07:00 | MASTER-SAAO | (02h 46m 11.98s , -27d 21m 31.4s) | C | 60 | 18.6 | 15571 | 2023-02-25 19:08:20 | MASTER-SAAO | (02h 54m 19.64s , -27d 21m 03.3s) | C | 60 | 18.5 | 15571 | 2023-02-25 19:08:20 | MASTER-SAAO | (02h 55m 20.26s , -27d 21m 32.7s) | C | 60 | 18.4 | 15662 | 2023-02-25 19:09:51 | MASTER-SAAO | (03h 13m 24.51s , -33d 01m 14.5s) | C | 60 | 18.5 | 15662 | 2023-02-25 19:09:51 | MASTER-SAAO | (03h 14m 29.06s , -33d 01m 43.0s) | C | 60 | 18.6 | 15742 | 2023-02-25 19:11:11 | MASTER-SAAO | (03h 22m 58.17s , -33d 02m 46.9s) | C | 60 | 18.8 | 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 31178] GRB 230217A: VLT/FORS2 optical observations and candidate counterpart
by GCN Circulars 24 Feb '23

24 Feb '23

TITLE: GCN CIRCULAR NUMBER: 33374 SUBJECT: GRB 230217A: VLT/FORS2 optical observations and candidate counterpart DATE: 23/02/24 15:50:32 GMT FROM: Paolo D'Avanzo at INAF-OAB <pda.davanzo(a)gmail.com> P. D'Avanzo, A. Rossi (INAF-OAS), R. Brivio (INAF-OAB), D. B. Malesani (Radboud Univ.and DAWN/NBI), A. Saccardi (GEPI, Observatoire de Paris), S. Campana (INAF-OAB), B. Gompertz (Univ. Birmingham), D. Hartmann (Clemson Univ.), D. A. Kann (Goethe Univ). A. J. Levan (Radboud Univ.), G. Tagliaferri (INAF-OAB), N. R. Tanvir (Univ. Leicester) report on behalf of the Stargate consortium: We observed the field of the short GRB 230217A (Moss et al. GCN Circ. 33339) with the ESO/VLT equipped with the FORS2 instrument. A series of optical images has been obtained with the I filter on 2023 February 20 (i.e. about 2.5 days after the burst) and on 2023 February 23 (i.e. about 5.5 days after the burst). Image subtraction carried out between the two epochs shows a residual at the following position: RA (J2000) = 18:43:04.97 Dec (J2000) = -28:50:16.4 +/- 0.3". This position lies inside the XRT error circle of the X-ray afterglow position (Capalbi et al., GCN Circ. 33365) and is consistent with the position of the radio source reported by Schroeder et al. (GCN Circ. 33358). From preliminary photometry, we measure for this source a magnitude of I ~ 24.5 (AB) at t-t0 = 2.5 days. We propose this source as a candidate optical counterpart of GRB 230217A. Further observations are planned. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Julia Seidel, Konrad Tristram and Thomas Rivinius.

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