[vsnet-grb-info 19852] IPN Triangulation of GRB 170921B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21918
SUBJECT: IPN Triangulation of GRB 170921B
DATE:    17/09/23 14:57:18 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova at mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 170921B (Bissaldi, GCN 21902) was detected
by Fermi (GBM trigger 527659336), Konus-Wind, INTEGRAL (SPI-ACS),
Mars-Odyssey (HEND), and Swift (BAT) at about 14531 s UT (04:02:11).
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:
   132.375 (08h 49m 30s) +57.057 (+57d 03' 24")
  Corners:
   112.726 (07h 30m 54s) +39.192 (+39d 11' 30")
   113.512 (07h 34m 03s) +41.297 (+41d 17' 50")
   162.356 (10h 49m 25s) +62.282 (+62d 16' 56")
   160.088 (10h 40m 21s) +62.030 (+62d 01' 49")
  ---------------------------------------------
The error box area is 8.7 sq. deg, and its maximum
dimension is 37.5 deg (the minimum one is 14.4 arcmin).
The Sun distance was 63 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB170921_T14528/IPN

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