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GCN Circular 39145

Subject

IPN triangulation of GRB 250204B (short/hard)

Date

2025-02-04T17:51:38Z (6 days 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, report:

The short-duration GRB 250204B
(Fermi-GBM detection: The Fermi GBM team, GCN 39141Loading...
 
 ;
AstroSat-CZTI detection: Dasgupta et al., GCN 39142Loading...
 
 )
was detected by Fermi (GBM trigger 760344078), AstroSat (CZTI),
Swift (BAT), Konus-Wind, and INTEGRAL (SPI-ACS)
at about 24074 s UT (06:41:14).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
    1.945 (00h 07m 47s) +35.469 (+35d 28' 07")
 Corners:
    4.715 (00h 18m 52s) +29.985 (+29d 59' 08")
    6.110 (00h 24m 26s) +29.936 (+29d 56' 11")
  358.613 (23h 54m 27s) +40.986 (+40d 59' 08")
  356.896 (23h 47m 35s) +41.060 (+41d 03' 34")
 ---------------------------------------------
The error box area is 13.4 sq. deg, and its maximum
dimension is 13.4 deg (the minimum one is 1 deg).
The Sun distance was 64 deg.

This localization may be improved.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM localization (GCN 39141Loading...
 
 ).

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB250204_T24073/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.