Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 35870

IPN triangulation of GRB 240229A
2024-03-05T14:06:31Z (5 months ago)
Dmitry Svinkin at Ioffe Institute <>
legacy email
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the MGNS/BepiColombo team,

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,

The long-duration GRB 240229A
(Fermi-GBM detection: The Fermi GBM team, GCN 35833;
BALROG localization: Biltzinger et al., GCN 35834;
CALET-CGBM detection: Yamaoka et al., GCN 35842)
was detected by Fermi (GBM trigger 730908432),
and BepiColombo (MGNS) at about 50827 s UT (14:07:07).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  RA(2000), deg                 Dec(2000), deg
  195.477 (13h 01m 54s) +12.791 (+12d 47' 26")
  194.744 (12h 58m 59s) +10.021 (+10d 01' 15")
  195.408 (13h 01m 38s) +10.063 (+10d 03' 46")
  196.123 (13h 04m 30s) +15.555 (+15d 33' 18")
  195.453 (13h 01m 49s) +15.513 (+15d 30' 45")
The error box area is 3.5 sq. arcmin, and its maximum
dimension is 5.7 deg (the minimum one is 38.3 arcmin).
The Sun distance was 146 deg.

The IPN localization is consistent with, but reduces the area of,
the final Fermi-GBM and the BALROG localizations.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at

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

Looking for U.S. government information and services? Visit