GCN Circular 44458
Subject
IPN triangulation of GRB 260428A
Event
Date
2026-05-04T15:04:29Z (5 months ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
Via
Web form
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
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,
C. Wang (IHEP), S. Xiong (IHEP), S. Zhang (IHEP),
J. Wei (NAOC), B. Cordier (CEA) on behalf of the SVOM-GRM team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:
The short-duration GRB 260428A
(Fermi-GBM detection: Fermi GBM team, GCN Circ. 44415;
AstroSat-CZTI detection: Goyal et al., GCN Circ. 44421;
GECAM-B detection: Wang et al., GCN Circ. 44423;
SVOM/GRM observation: Wang et al., GCN Circ. 44424)
was detected by Fermi (GBM), Konus-Wind, AstroSat (CZTI),
GECAM-B, SVOM (GRM), and Mars-Odyssey (HEND)
at about 51636 s UT (14:20:36).
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
283.386 (18h 53m 33s) +0.365 ( +0d 21' 53")
Corners:
283.274 (18h 53m 06s) +1.978 ( +1d 58' 41")
283.221 (18h 52m 53s) +2.065 ( +2d 03' 56")
283.504 (18h 54m 01s) -1.335 ( -1d 20' 06")
283.558 (18h 54m 14s) -1.435 ( -1d 26' 07")
---------------------------------------------
The error box area is 561 sq. arcmin, and its maximum
dimension is 3.5 deg (the minimum one is 3 arcmin).
The Sun distance was 111 deg.
A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB260428_T51639/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.