GRB 250114B
GCN Circular 38938
Subject
GRB 250114B: a short GRB detected with INTEGRAL
Date
2025-01-14T14:08:18Z (5 months ago)
From
Diego Gotz at CEA <diego.gotz@cea.fr>
Via
Web form
D.Gotz (CEA, Saclay), S.Mereghetti (INAF, IASF-Milano), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report:
a short gamma ray burst lasting about 1 s has been detected by IBAS in the IBIS/ISGRI data at 13:15:37 UT of 2025 January 14.
The refined coordinates (J2000) are:
R.A.= 48.8765 deg
DEC.= -2.3074 deg
with an uncertainty of 2.1 arcmin (90% c.l.).
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 38941
Subject
GRB 250114B: Swift ToO observations
Date
2025-01-14T16:26:10Z (5 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the INTEGRAL GRB 250114B.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021756
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 INTEGRAL 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.
GCN Circular 38942
Subject
GRB 250114B : GIT optical upper limit
Date
2025-01-14T16:28:42Z (5 months ago)
From
V. Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>
Via
Web form
M. Goyal, A.P. Saikia, V. Swain, T. Mohan, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:
We observed the field of INTEGRAL GRB 250114B (Gotz et. al., GCN 38938) with 0.7m GROWTH-India Telescope (GIT) in r' filter. We started the observation at 2025-01-14 14:43:01 UT, i.e., 1.46 hours after the INTEGRAL trigger. We did not detect any new source in our stacked image within the uncertainty region reportedd in GCN 38938. The obtained upper limit is as follows:
| MJD (mid) | Filter | Exposure (s) | Limiting Magnitude (AB) |
| ----------------- |------- | ------------------ | -------------- |
| 60689.62099 | r' | 3 x 300 | 20.3 |
The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN Circular 38947
Subject
GRB 250114B: OHP/T193 optical upper limit
Date
2025-01-14T22:47:18Z (5 months ago)
From
Benjamin Schneider at MIT <bschn@mit.edu>
Via
Web form
B. Schneider (LAM), C. Adami (LAM/Pytheas/AMU), S. Basa (LAM/OHP/Pytheas/AMU), E. Le Floc'h (CEA), A. Saccardi (CEA), D. Turpin (CEA) report on behalf of a larger collaboration:
We observed the field of the INTEGRAL GRB 250114B (Gotz et al., GCN 38938) with the T193cm telescope at the Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. We obtained a total of 61 minutes (1x300s + 4x180s + 11x240s) in the i-band using the red MISTRAL setting from 2025-01-14T18:08 to 2025-01-14T19:29 (mid-time 5.6h after the trigger).
In the stacked image, we do not detect any new source at the XRT #2 source position (Evans et al., GCN 38941) or within the INTEGRAL error circle (Gotz et. al., GCN 38938) down to the following 5-sigma limit:
i > 20.88 mag (AB)
The photometric calibration was performed using nearby stars from the PanSTARRS catalog.
We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Balcaen, Orlagh Creevey and Flavien Kiefer.
GCN Circular 38949
Subject
GRB 250114B: Swift-XRT observations
Date
2025-01-15T10:01:45Z (5 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
M. A. Williams (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B.
Sbarufatti (INAF-OAB) and P.A. Evans (U. Leicester) reports on behalf
of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 250114B, collecting 5.3 ks of Photon Counting (PC) mode data
between T0+11.3 ks and T0+44.6 ks.
One uncatalogued X-ray source has been detected within the estimated
3-sigma INTEGRAL error region (197 arcsec), 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 2:
RA (J2000.0): 48.8582 = 03:15:25.96
Dec (J2000.0): -2.2940 = -02:17:38.2
Error: 7.6 arcsec (radius, 90% conf.)
Count-rate: (2.62 [+1.04, -0.84])e-3 ct s^-1
Distance: 81 arcsec from INTEGRAL position.
Flux: (1.33 [+0.53, -0.43])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Two 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/00021756.
This circular is an official product of the Swift-XRT team.
GCN Circular 38950
Subject
GRB 250114B : MITSuME Akeno optical afterglow candidate detection
Date
2025-01-15T10:30:38Z (5 months ago)
From
Mahito Sasada at Tokyo Institute of Technology <sasada@hp.phys.titech.ac.jp>
Via
Web form
M. Sasada, I. Takahashi, H. Hagio, Y. Kubo, N. Higuchi, H. Seki, S. Joshima, Y. Yatsu and N. Kawai (Science Tokyo) report on behalf of the MITSuME collaboration:
We observed the field of GRB 250114B (Gotz et al. GCN 38938; Evans et al. GCN 38941) with the optical three-color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50-cm telescope Akeno.
The observation started at 2025-01-14 13:16:36.51 UT (60 seconds after the INTEGRAL trigger). We stacked the images with good conditions. Then we detected a point source in the Rc- and Ic-band images within the circle of INTEGRAL uncertainty area (Gotz et al. GCN 38938). The source position is R.A. = 48.8582 deg and Dec. = -2.2936 deg, which is consistent with the 2nd X-ray source position of R.A. = 48.8582 deg and Dec. = -2.2940 deg detected by XRT within 1 arcsec (Evans et al. GCN 38941; Williams et al. GCN 38949). Here we report upper limits of the observations, and magnitudes of the source as follows.
T0+[sec] | MID-UT | T-EXP[sec] | 5-sigma limits and magnitudes
------------------------------------------------------------------------------------------------
399 | 2025-01-14 13:22:16.31 | 480 | g'>18.0, Rc=18.1+/-0.1, Ic=17.6+/-0.1
2232 | 2025-01-14 13:52:49.03 | 2460 | g'>18.6, Rc=19.4+/-0.2, Ic=19.1+/-0.2
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the trigger
T-EXP: Total Exposure time
We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g', Rc and Ic band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ; https://github.com/MNiwano/Eclaire).
GCN Circular 38952
Subject
GRB 250114B: Liverpool Telescope optical upper limit
Date
2025-01-15T12:43:55Z (5 months ago)
From
Ben Gompertz at U of Birmingham <b.gompertz@bham.ac.uk>
Via
email
B. P. Gompertz (U. Birmingham), Dimple (U. Birmingham), D. B. Malesani (DAWN/NBI and Radboud) and A. J. Levan (Radboud) report:
We initiated follow-up observations of the INTEGRAL-detected GRB 250114B (Gotz et al., GCN 38938) with the IO:O camera on the 2m robotic Liverpool Telescope (LT). Observations began at 19:17:04 UT on 2025-01-14 and consisted of 5x120 s exposures in the SDSS r filter.
We do not detect the candidate afterglow reported by MITSuME Akeno (Sasada et al., GCN 38950) nor any new source within the localisation region of XRT source 2 (Williams et al., GCN 38949) to a 3-sigma limiting magnitude of r(AB) > 21.17, at a mid-time of 6.24 hr after trigger. Observations were calibrated against nearby SDSS stars and are not corrected for foreground extinction.
Our non-detection, and those reported by GIT (Goyal et al., GCN 38942) and OHP/T193 (Schneider et al., GCN 38947), support the rapid fading detected by MITSuME Akeno over a longer time baseline, indicating the source is likely the optical afterglow of GRB 250114B.
In Legacy Survey images of the field there is no object directly underlying the afterglow position. The closest object is a galaxy with r = 24.4 and an offset of ~1.5 arcseconds. This galaxy has a probability of chance alignment of ~5% (cf. Bloom et al. 2002, ApJ, v123, p1111).
GCN Circular 38960
Subject
GRB 250114B: SVOM/VT upper limit
Date
2025-01-16T07:48:38Z (4 months ago)
From
Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Via
Web form
SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, Z. H. Yao, Y. N. Ma (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), Diego Götz, Bertrand Cordier (CEA)
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV)
report on behalf of the SVOM team:
The SVOM/VT conducted a ToO observations of the INTEGRAL-detected GRB 250114B (Gotz et al., GCN 38938) . The observations were carried out in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously.
The afterglow reported (Williams et al., GCN 38949; Sasada et al., GCN 38950) was not detected either in VT_B or VT_R stacked images.
The 3 sigma limits in AB magnitude were derived with VT_B= 23.9 mag with exposure time of 37*100 sec and VT_R= 23.6 mag with exposure time of 35*100 sec, at the mid time of about 24.0 hours after the burst.
The non-detection is consistent with the reports (Goyal et al., GCN 38942; Schneider et al., GCN 38947; Gompertz et al., GCN 38952).
The galaxy noticed (Gompertz et al., GCN 38952) was marginal detected in VT_R stacked image.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS.
GCN Circular 38961
Subject
GRB 250114B: Swift-XRT afterglow detection
Date
2025-01-16T14:28:12Z (4 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
M. A. Williams (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B.
Sbarufatti (INAF-OAB) and P.A. Evans (U. Leicester) reports on behalf
of the Swift-XRT team:
Swift-XRT has conducted further observations of the field of the
INTEGRAL-detected burst GRB 250114B. The observations now extend from
T0+11.4 ks to T0+153.7 ks and have a total exposure time of 9.8 ks. .
The source previously reported, "Source 2", is believed to be the
afterglow. The position of this source is RA, Dec=48.8582, -2.2940
which is equivalent to:
RA (J2000): 03:15:25.96
Dec(J2000): -02:17:38.2
with an uncertainty of 7.6 arcsec (radius, 90% confidence). This
position is 81 arcsec from the INTEGRAL position and consistent with
the reported optical counterpart (Sasada et al. GCN 38950). Comparison
of individual observations show the source has faded.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021756.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021756.
This circular is an official product of the Swift-XRT team.