GCN Circular 35311

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,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT 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 very bright, long-duration GRB 231129C
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 35217
Not found
 
 
;
Sharma et al., GCN Circ. 35221
Not found
 
 
, 35227
Not found
 
 
;
BALROG localization: Preis et al., GCN Circ. 35222
Not found
 
 
;
MAXI-GSC detection: Kawakubo et al., GCN Circ. 35223
Not found
 
 
;
CALET-CGBM detection: Shimizu et al., GCN Circ. 35228
Not found
 
 
;
AstroSat-CZTI detection: Waratkar et al., GCN Circ. 35230
Not found
 
 
;
GECAM-B detection: Zheng and Xiong, GCN Circ. 35231
Not found
 
 
;
Glowbug detection: Cheung et al., GCN Circ. 35235
Not found
 
 
;
GRBAlpha detection: Dafcikova et al., GCN Circ. 35236
Not found
 
 
;
Fermi-LAT detection: Arimoto et al., GCN Circ. 35238
Not found
 
 
;
Swift-BAT/GUANO detection: DeLaunay et al., GCN Circ. 35242
Not found
 
 
;
AGILE detection: Panebianco et al., GCN Circ. 35244
Not found
 
 
;
Konus-Wind detection: Lysenko et al., GCN Circ. 35256
Not found
 
 
;
ASIM-MXGS detection: Marisaldi et al., GCN Circ. 35288
Not found
 
 
)
was detected by Fermi (GBM, LAT), ISS (Glowbug, CALET-CGBM),
AstroSat (CZTI), GECAM-B (GRD), GRBAlpha, AGILE (MCAL, AC),
Swift (BAT), Konus-Wind, INTEGRAL (SPI-ACS),
GRBAlpha, Mars-Odyssey (HEND), and BebiColombo (MGNS)
at about 69018 s UT (19:10:18).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
    9.975 (00h 39m 54s) -81.812 (-81d 48' 43")
 Corners:
    4.821 (00h 19m 17s) -80.799 (-80d 47' 56")
   16.263 (01h 05m 03s) -82.675 (-82d 40' 29")
   16.443 (01h 05m 46s) -82.746 (-82d 44' 45")
    4.881 (00h 19m 31s) -80.873 (-80d 52' 23")
 ---------------------------------------------
The error box area is 322 sq. arcmin, and its maximum
dimension is 2.5 deg (the minimum one is 2.2 arcmin).
The Sun distance was 73 deg.

This localization may be improved.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM/LAT and ASIM localizations.

The Swift-XRT reported Source 2 (GCN 35234
Not found
 
 
, 35251
Not found
 
 
) is inside the IPN box, supporting that the source is the afterglow of GRB 231129C.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB231129_T69016/IPN/