[vsnet-grb-info 28438] IPN triangulation of GRB 210727A (short)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30541
SUBJECT: IPN triangulation of GRB 210727A (short)
DATE:    21/07/28 18:09:24 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia at mail.ioffe.ru>

A. Ridnaia, S. Golenetskii, D. Frederiks, D. Svinkin,
A. Lysenko, and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
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, and

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

The short-duration GRB 210727A
(BALROG localization: Biltzinger et al., GCN 30531;
AGILE-MCAL detection: Ursi et al., GCN 30533)
was detected by Fermi (GBM trigger 649072251), Konus-Wind,
INTEGRAL (SPI-ACS), Swift (BAT), AGILE (MCAL),
and CALET (CGBM) at about 35447 s UT (09:50:47).
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:
  189.231 (12h 36m 55s) -59.926 (-59d 55' 35")
 Corners:
  194.539 (12h 58m 09s) -56.353 (-56d 21' 12")
  193.795 (12h 55m 11s) -56.308 (-56d 18' 30")
  182.624 (12h 10m 30s) -63.300 (-63d 17' 59")
  183.549 (12h 14m 12s) -63.394 (-63d 23' 37")
 ---------------------------------------------
The error box area is 3.28 sq. deg, and its maximum
dimension is 9.14 deg (the minimum one is 22 arcmin).
The Sun distance was 93 deg.

This box may be improved.

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

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB210727_T35447/IPN

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