TITLE:   GCN CIRCULAR
NUMBER:  30993
SUBJECT: IPN Triangulation of GRB 211019A
DATE:    21/10/25 15:02:56 GMT
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 MGNS/BepiColombo and HEND/Mars Odyssey teams,

J. Benkhoff on behalf of the BepiColombo team,

K. Hurley on behalf of the IPN,

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

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

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

The bright, long-duration GRB 211019A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 30941;
BALROG localization: F. Kunzweiler et al., GCN Circ. 30942;
GRBAlpha detection: J. Ripa et al., GCN Circ. 30946)
was detected by BepiColombo (MGNS; see introductory GCN Circ. 30949),
Mars-Odyssey (HEND), GRBAlpha, Fermi (GBM trigger 656315976),
Konus-Wind, and INTEGRAL (SPI-ACS), at about 21571 s UT (05:59:31).

The burst light curves in the energy range 30 keV-1.5 MeV (HEND) and
250-450 keV (MGNS) exhibit a bright peak with a total duration of ~17 s.

We have triangulated GRB 211019A to the following 3 sigma annuli:
---------------------------------------------------------
           R.A.(J2000)  Dec.(J2000)    R      +dR     -dR
               deg         deg        deg     deg     deg
---------------------------------------------------------
MGNS-HEND    27.190     10.927     89.034  +0.021  -0.022
Konus-HEND  200.705     -8.093     87.815  +0.017  -0.017
Konus-GBM   190.965     -7.594     80.456  +0.431  -0.431
---------------------------------------------------------
The MGNS-HEND and Konus-HEND annuli intersect to form two error
boxes one of which is inconsistent with the Konus-GBM annulus,
the KW ecliptic latitude response,
and the Fermi (GBM) RoboBA and BALROG localizations.

The correct preliminary, 3 sigma error box is:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   106.988 (07h 07m 57s) -38.779 (-38d 46' 43")
  Corners:
   106.975 (07h 07m 54s) -38.728 (-38d 43' 41")
   106.898 (07h 07m 36s) -39.122 (-39d 07' 19")
   107.002 (07h 08m 01s) -38.819 (-38d 49' 07")
   107.079 (07h 08m 19s) -38.424 (-38d 25' 25")
  ---------------------------------------------
The error box area is 49 sq. arcmin, and its maximum
dimension is 43 arcmin (the minimum one is 2.0 arcmin).
The Sun distance was 89 deg.

This box may be improved.

A triangulation maps are posted at:
http://www.ioffe.ru/LEA/GRBs/GRB211019_T21573/IPN/
and
http://l503.iki.rssi.ru/owncloud/index.php/s/bRzLdux7RLz1tVf