[vsnet-grb-info 14691] GRB 140320B: ISON-NM optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16005
SUBJECT: GRB 140320B: ISON-NM optical observations
DATE:    14/03/20 11:15:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

L. Elenin (KIAM),  A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko 
(IKI) report on behalf of larger GRB  follow-up collaboration:

We observed of  the field of  the INTEGRAL GRB 140320B (Mereghetti et 
al.,  GCN 16004)  with 0.4-m telescope of ISON-NM observatory starting 
on Mar., 20 (UT)  09:35:41.  We took unfiltered images of 30 s 
exposures. We detect a fading optical afterglow of GRB  140320B 
(Guidorzi  et al.,   GCN 16003) in a stacked image of total exposure 300 
s and do not detect it in the next stacked image of the same exposure. 
  Coordinates of the optical afterglow (J2000) 09 42 13.96 +60 16 05.9 
(uncertainties of 1 arcsec) coincide with OT coordinates (Guidorzi et 
al.,  GCN 16003). Preliminary photometry  of first stacked images is 
based on nearby USNO-B1.0 stars:

UT mid,      T0+      Filter  Exposure,  OT,    err OT
                  mid          s
09:38:39      0.00878 none    10Ñ
30     19.1    0.2
09:44:40      0.03102 none    10Ñ
30   > 19.3    UpperlLimit