[vsnet-grb-info 17344] GRB 151221A: INTEGRAL detection of a short burst or possible SGR

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18711
SUBJECT: GRB 151221A: INTEGRAL detection of a short burst or possible SGR
DATE:    15/12/21 10:18:14 GMT
FROM:    Sandro Mereghetti at IASF/CNR  <sandro at iasf-milano.inaf.it>

S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, 
E.Bozzo (ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the 
IBAS Localization Team report:

a gamma ray burst lasting about 50 ms has been detected by IBAS in the 
IBIS/ISGRI data at 02:51:12.7 UT of December 21, 2015 with a significance 
below the threshold for automatic alert delivery (IBAS Weak Alert n.7313)

The refined coordinates (J2000) are:

R.A.=  293.7327 deg
DEC.=  21.8843 deg


with an uncertainty of 2 arcmin (90% c.l.).

The burst had a fluence of about 4e-8 erg/cm2 (20-200 keV, 0.1-s 
integration time).

The soft spectrum, short duration, low galactic latitude and position 
inside the supernova remnant G57.2+0.8 suggest taht this event could be 
due to a new Soft Gamma-ray Repeater.

A plot of the light curve will  be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html