GCN Circular 39144
Subject
IPN triangulation of GRB 250202B
Event
Date
2025-02-04T17:46:35Z (a year ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
Via
Web form
D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,
A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,
E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
G. Waratkar, J.Joshi, V. Bhalerao, D. Bhattacharya,
and S. Vadawale, on behalf of the Astrosat-CZTI team,
and
S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:
The bright long-duration GRB 250202B
(Fermi-GBM detection: The Fermi GBM team, GCN 39120;
Bala et al., GCN 39133;
AstroSat-CZTI detection: Srijan et al., GCN 39122;
NuSTAR-ACS detection: Grefenstette, GCN 39135)
was detected by Fermi (GBM trigger 760161442), AstroSat (CZTI),
Swift (BAT), Konus-Wind, and INTEGRAL (SPI-ACS)
at about 14237 s UT (03:57:17).
The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
344.999 (22h 60m 00s) +19.593 (+19d 35' 35")
Corners:
343.557 (22h 54m 14s) +22.051 (+22d 03' 04")
347.168 (23h 08m 40s) +17.149 (+17d 08' 56")
346.317 (23h 05m 16s) +17.129 (+17d 07' 44")
342.644 (22h 50m 34s) +22.024 (+22d 01' 27")
---------------------------------------------
The error box area is 4.1 sq. deg, and its maximum
dimension is 6.5 deg (the minimum one is 41.5 arcmin).
The Sun distance was 45 deg.
This localization may be improved.
The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM (GCN 39120) localization.
A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB250202_T14235/IPN
The HEALPix triangulation map is the multi-order HEALPix in units of
probability density.
The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.