GCN Circular 33480

Subject
IPN triangulation of GRB 230304B
Event
Date
2023-03-15T14:52:07Z (3 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the MGNS/BepiColombo and HEND/Mars Odyssey teams,

J. Benkhoff on behalf of the BepiColombo team,

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
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,

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 230304B
(Fermi-GBM detection: the Fermi GBM team, GCN Circ. 33396Loading...
 
 ;
GRBAlpha detection: Dafcikova et al., GCN Circ. 33398Loading...
 
 ;
AstroSat-CZTI detection: Navaneeth et al., GCN Circ. 33400Loading...
 
 ;
CALET-GBM detection: Kobayashi et al., GCN Circ. 33423Loading...
 
 )
was detected by Fermi (GBM trigger 699633354),
Konus-Wind, INTEGRAL (SPI-ACS), GRBAlpha, AstroSat (CZTI),
CALET (GBM), BepiColombo (MGNS), and Mars-Odyssey (HEND),
at about 52549 s UT (14:35:49).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   110.440 (07h 21m 46s)  -2.113 ( -2d 06' 48")
  Corners:
   110.528 (07h 22m 07s)  -2.101 ( -2d 06' 03")
   110.345 (07h 21m 23s)  -2.288 ( -2d 17' 16")
   110.352 (07h 21m 24s)  -2.126 ( -2d 07' 33")
   110.535 (07h 22m 08s)  -1.938 ( -1d 56' 16")
  ---------------------------------------------
The error box area is 103 sq. arcmin, and its maximum
dimension is 24 arcmin (the minimum one is 6.5 arcmin).
The Sun distance was 124 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final localization (GCN 33396Loading...
 
 ).

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230304_T52553/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.