GCN Circular 44121

Subject
IPN triangulation of GRB 260320A
Event
GRB 260320A
Date
2026-03-26T23:15:43Z (10 hours ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@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,

D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

E. Burns on behalf of the IPN,

C. Wang (IHEP), S. Xiong (IHEP), S. Zhang (IHEP),
J. Wei (NAOC),  B. Cordier (CEA) on behalf of the SVOM-GRM team,

C. Wang (IHEP), S. Xiong (IHEP), S. Zhang (IHEP)
on behalf of the Insight-HXMT 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 long-duration GRB 260320A
(NuSTAR-ACS detection: Waratkar et al., GCN 44064Loading...
 
 ;
Insight-HXMT/HE detection: Luo et al., GCN 44077Loading...
 
 ;
Glowbug detection: Cheung et al., GCN 44093Loading...
 
 ;
GRID detection: Li et al., GCN 44109Loading...
 
 )
was detected by NuSTAR (ACS), SVOM (GRM), Insight-HXMT(HE),
Konus-Wind, Glowbug, GRID-11B, GRID-10B, and Mars-Odyssey (HEND)
at about 70804 s UT (19:40:04).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
  RA(2000), deg         Dec(2000), deg
---------------------------------------------
Center:
  316.117 (21h 04m 28s) +6.388 ( +6d 23' 17")
Corners:
  318.993 (21h 15m 58s) +11.535 (+11d 32' 06")
  313.686 (20h 54m 45s)  -0.693 (+00d 41' 36")
  313.683 (20h 54m 44s)  -1.165 (-01d 09' 54")
  318.941 (21h 15m 46s) +11.286 (+11d 17' 09")
---------------------------------------------
The error box area is 1.3 sq. deg, and its maximum
dimension is 13.8 deg (the minimum one is 5.7 arcmin).
The Sun distance was 42 deg.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB260320_T70801/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.