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

[vsnet-grb-info 31519] GRB 230430A: Fermi GBM Final Real-time Localization
by GCN Circulars 30 Apr '23

30 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33713 SUBJECT: GRB 230430A: Fermi GBM Final Real-time Localization DATE: 23/04/30 07:57:58 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 07:47:18 UT on 30 Apr 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230430A (trigger 704533643.80535 / 230430325). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 184.2, Dec = 40.8 (J2000 degrees, equivalent to J2000 12h 16m, 40d 47'), with a statistical uncertainty of 2.5 degrees. The angle from the Fermi LAT boresight is 22.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230430325/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230430325/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230430325/…

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[vsnet-grb-info 31518] GRB 230427A: NOT optical upper limit
by GCN Circulars 29 Apr '23

29 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33712 SUBJECT: GRB 230427A: NOT optical upper limit DATE: 23/04/29 15:45:11 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> Z.P. Zhu (NAOC, HUST), D. B. Malesani (Radboud Univ. and DAWN/NBI), X. Liu, D. Xu (NAOC), report on behalf of a larger collaboration: We observed the field of GRB 230427A detected by Swift (Troja et al., GCN 33687) using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations started at 23:06:58 UT on 2023-04-27, i.e., ~12.6 hr after the Swift/BAT trigger, and 3x300 s Sloan r-filter images and 5x200 s Sloan z-filter images were obtained, respectively. No new source is detected in our stacked images at the Swift/UVOT position (Troja et al., GCN 33687), and preliminary photometric results are as follows: T_mid-T0 (hr) Filter Upper_Limit (3-sigma) 12.7 r >23.5 13.0 z >22.5 calibrated with the nearby Pan-STARRS field and not corrected for Galactic extinction.

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[vsnet-grb-info 31517] GRB 230427A: TSHAO, SAO RAS, AbAO optical upper limit
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33711 SUBJECT: GRB 230427A: TSHAO, SAO RAS, AbAO optical upper limit DATE: 23/04/28 21:28:46 GMT FROM: Alexei Pozanenko at IKI, Moscow <apozanen(a)iki.rssi.ru> I. Reva (FAP), A. S. Moskvitin (SAO RAS), O. A. Maslennikova (SAO RAS), R. Ya. Inasaridze (AbAO), A. Volnova (IKI), A. Pozanenko (IKI), N. Pankov (HSE), S. Belkin (IKI) report on behalf of GRB IKI FuN: We observed the field of Swift GRB 230427A (Troja et al., GCN 33687) in R-filter on 2023-04-27 starting (UT) 15:09:59 with with Zeiss-1000 telescope of TSHAO observatory, (UT) 17:21:56 with Zeiss-1000 telescope of SAO RAS, (UT) 21:56:16 with AS-32 telescope of Abastumani observatory. We do not detect the optical counterpart of GRB 230427A (Troja et al., GCN 33687; Hu et al., GCN 33695; Agui Fernandez et al., GCN 33704; Klingler et al., GCN 33710). Preliminary photometry of stacked images is following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) Obs. (mid, days) (s) 2023-04-27 15:09:59 0.22388 37*120 R n/d n/d 21.8 TSAHO 2023-04-27 17:21:56 0.30117 4*300 R n/d n/d 21.4 SAO RAS 2023-04-27 21:56:16 0.51140 104*60 R n/d n/d 21.0 AbAO The photometry is based on nearby USNO-B1.0 stars. USNO-B1.0 R2 1381-0248742 15.71 1381-0240666 16.93 1381-0240629 16.83

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[vsnet-grb-info 31516] GRB 230427A: Swift/UVOT Detection
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33710 SUBJECT: GRB 230427A: Swift/UVOT Detection DATE: 23/04/28 18:03:41 GMT FROM: N. Klingler at NASA-GSFC/UMBC/CRESST II <noelklingler(a)gmail.com> N. J. Klingler (GSFC/UMBC/CRESTII) and E. Troja (UToV) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 230427A 98 s after the BAT trigger (Troja et al., GCN Circ. 33687). A source consistent with the XRT position (Evans et al. 2023, GCN Circ. 33688) is detected in the initial UVOT exposures. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 98 248 147 20.19 +/- 0.15 v 586 4999 255 >19.3 b 512 1158 58 >19.6 u 256 854 265 >20.5 w1 810 5404 231 >20.0 m2 5004 5204 197 >19.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.007 in the direction of the burst (Schlegel et al. 1998).

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[vsnet-grb-info 31515] GRB 230216A: Swift/UVOT Upper Limits
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33709 SUBJECT: GRB 230216A: Swift/UVOT Upper Limits DATE: 23/04/28 17:55:29 GMT FROM: noelklingler(a)gmail.com N. Klingler (GSFC/UMBC/CRESTII) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 230216A 106 s after the BAT trigger (Klingler et al., GCN Circ. 33328). No optical afterglow consistent with the optical position (Gendre et al. GCN Circ. 33329) is detected in the initial UVOT exposures. 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 106 256 147 >16.9 u_FC 264 514 246 >16.9 white 106 1188 353 >16.8 v 594 1065 58 >15.9 b 520 1164 58 >16.5 u 264 1139 304 >16.9 w1 643 1114 58 >17.1 m2 618 1090 58 >17.6 w2 569 1213 78 >17.7 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.198 in the direction of the burst (Schlegel et al. 1998).

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[vsnet-grb-info 31514] GRB 230427A: Gaoyazi/GOT optical upper limit
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33708 SUBJECT: GRB 230427A: Gaoyazi/GOT optical upper limit DATE: 23/04/28 15:42:19 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> S.Y. Fu, S.Q. Jiang, X. Liu, T.H. Lu, D Xu (NAOC), Z.P. Zhu (NAOC, HUST), S.W. Luo, M.M. Yang, Z. K. Feng (GYZO, NAOC) report: We observed the field of GRB 230427A detected by Swift (Troja et al., GCN 33687) with the GOT-0.5m telescope located at Gaoyazi, Xinjiang, China. Observations started at 16:34:35 UT on 2023-04-27, i.e., 6.05 hr after the Swift/BAT trigger, 5 x 90 s and 10 x 120 s images were obtained in the Sloan r filter. No optical source is detected in our stacked image at the UVOT position (Troja et al,. GCN 33687), down to a 3-sigma limiting magnitude r > 20.4 (AB) at 6.32 hr post-burst, calibrated with nearby PanSTARRS stars. The magnitude is not corrected for Galactic extinction.

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[vsnet-grb-info 31513] GRB 230427A: OHP/T193 spectroscopy observations of WISEA J101316.01+481158.7
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33707 SUBJECT: GRB 230427A: OHP/T193 spectroscopy observations of WISEA J101316.01+481158.7 DATE: 23/04/28 15:40:52 GMT FROM: Benjamin Schneider at MIT <bschn(a)mit.edu> C. Adami, M. Garnichey, F. Michel (LAM), B. Schneider (MIT), S. Basa (LAM), S. D. Vergani (GEPI, Obs. de Paris), D. Turpin, D. Götz, E. Le Floc'h (CEA Paris-Saclay), report on behalf of a larger collaboration: We re-observed the field of GRB 230427A (Troja et al., GCN 33687) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. This time, we targeted in spectroscopy the galaxy close to the GRB line of sight: WISEA J101316.01+481158.7, at r'SDSS(PSF) = 19.6 (AB). Two exposures of 900s were obtained in the blue configuration (4200A-8000A) from 2023 28 April 00:25:02 UT to 2023 28 April 00:55:59 UT. The wavelength calibration was performed using the MISTRAL calibration lamp, exposed just after the science observation. Data were reduced using the ASPIRED package (https://github.com/cylammarco/ASPIRED) configured for MISTRAL data. In the combined frame, we clearly detect the [NII]@6548A, Halpha, [NII]@6583A, and [SII]@6718A. Halpha is the dominant line of the spectrum. Based on these lines, we inferred a redshift of z = 0.1524 +/- 0.0005, in good agreement with the SDSS photometric redshift of z = 0.13 +/- 0.03. The GRB is at an offset of ~18 arcsec from the WISEA J101316.01+481158.7 center. At the redshift of this galaxy, the burst would have a projected offset of ~48 kpc and a probability of chance coincidence of ~0.16, which is not commonly observed for the long GRB population. For this reason, this object is probably not the host galaxy of GRB 230427A. We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Balcaen.

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[vsnet-grb-info 31512] GRB 230427A: Nanshan/HMT optical upper limit
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33706 SUBJECT: GRB 230427A: Nanshan/HMT optical upper limit DATE: 23/04/28 15:38:03 GMT FROM: Dong Xu at NAOC/CAS <dxu(a)nao.cas.cn> S.Q. Jiang, S.Y. Fu, X. Liu, T.H. Lu, D. Xu (NAOC), Z.P. Zhu (NAOC, HUST), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of GRB 230427A detected by Swift (Troja et al., GCN 33687) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 14:50:24 UT on 2023-04-27, i.e., 4.3 hr after the Swift/BAT trigger, and 30x60 s unfiltered frames were obtained. No optical source is detected in our stacked image at the UVOT position (Troja et al., GCN 33687), down to a 3-sigma limiting magnitude m(r) > 21.1 mag (AB) at 4.7 hr post-burst, calibrated with the nearby PanSTAR field in the Sloan r-filter. The magnitude is not corrected for Galactic extinction.

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[vsnet-grb-info 31511] GRB 230427A: Osservatorio Astronomico Nastro verde upper limit
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33705 SUBJECT: GRB 230427A: Osservatorio Astronomico Nastro verde upper limit DATE: 23/04/28 15:20:54 GMT FROM: Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde(a)gmail.com> Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy in a large collaboration with: M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), B. De Simone (Universita' degli Studi Di Salerno) report: We image the field of GRB 230427A detected by SWIFT(trigger 1165948) with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy. Member of: AAVSO - American Association of Variable Star Observers. UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili. AstroCampania Associazione The observations started at 19:04 UT of 2023/04/27, after 8,30 hours after the GRB trigger, at the end of twilight with principal telescope SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME I took 32 image of 120 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker software We have not detected any clearly visible sources, up to 20th magnitude with lightly hazy skies and lunar disturbance Start T0+ End T0+ Rlim 19:04:53 UT 20:22:52 UT 20 We did not found any optical counterpart in the error box of the XRTcandidate. Troja et al., GCN 33687 Magnitudes were estimated with the Gaia DR2 cat. and are not corrected for galactic dust extinction. The message may be cited.

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[vsnet-grb-info 31510] GRB 230427A: OSIRIS+/GTC observations
by GCN Circulars 28 Apr '23

28 Apr '23

TITLE: GCN CIRCULAR NUMBER: 33704 SUBJECT: GRB 230427A: OSIRIS+/GTC observations DATE: 23/04/28 15:05:51 GMT FROM: J. F. Agui Fernandez at IAA-CSIC <feli(a)iaa.es> J. F. Agui Fernandez (IAA-CSIC), A. de Ugarte Postigo (OCA), C. C. Thoene (ASU-CAS), Fabricio Perez, Alvaro Tejero and A. L. Cabrera Lavers (GTC, IAC) report: We observed the afterglow of GRB 230427A at ~ 11.3 hours after burst (Page et al. GCN 33687; Takahashi et al. GCN 33690; Hu et al. GCN 33695; Tohuvavohu et al. 33703) with OSIRIS+ at the 10.4m GTC telescope, at the Roque de los Muchachos Observatory (La Palma, Spain). Observations consisted of 3x1200 s spectroscopy with grism R1000B, covering the spectral range between 3700 and 7800 AA under good observing conditions. From the acquisition image we detect a source at the GRB location and we measure a magnitude of r ~ 24.2 compared to PanSTARRS field stars. We detect a faint trace at GRB location above ~3950A which set a limit for the redshift of z < 3.3.

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vsnet-grb-info April 2023