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GCN Circular 33059

Subject
IPN triangulation of GRB 221209A (long)
Date
2022-12-15T16:29:48Z (a year 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 HEND/Mars Odyssey 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 bright, long-duration GRB 221209A
(Fermi-GBM detection: the Fermi GBM team, GCN Circ. 33031Not found
 
 
;
Bissaldi, GCN Circ. et al., GCN Circ. 33034Not found
 
 
;
BALROG localization: Kunzweiler et al., GCN Circ. 33032Not found
 
 
;
AstroSat-CZTI detection: Gopalakrishnan et al., GCN Circ. 33037Not found
 
 
;
CALET-CGBM detection: Kawakubo et al., GCN Circ. 33049Not found
 
 
)
was detected by Fermi(GBM trigger 692257829), Konus-Wind,
INTEGRAL (SPI-ACS), AstroSat (CZTI), CALET (CGBM),
and Mars-Odyssey (HEND) at about 21024 s UT (05:50:24).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   231.643 (15h 26m 34s) +49.850 (+49d 50' 59")
  Corners:
   230.092 (15h 20m 22s) +49.310 (+49d 18' 36")
   230.747 (15h 22m 59s) +49.761 (+49d 45' 38")
   233.222 (15h 32m 53s) +50.361 (+50d 21' 41")
   232.541 (15h 30m 10s) +49.930 (+49d 55' 48")
  ---------------------------------------------
The error box area is 1573 sq. arcmin, and its maximum
dimension is 2.28 deg (the minimum one is 15.5 arcmin).
The Sun distance was 76 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final localization (GCN 33034Not found
 
 
) and the BALROG localization 
(33032).

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB221209_T21024/IPN/

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