[vsnet-grb-info 13976] GRB 131002A: ISON-NM optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15290
SUBJECT: GRB 131002A: ISON-NM optical observations
DATE:    13/10/02 19:06:52 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 optical transient(Guidorzi et al., GCN 15282)  of  the Swift 
GRB 131002A (Barlow et al., GCN 15283)  with 0.4-m SANTEL-400AN 
telescope of ISON-NM observatory starting on Oct., 2 (UT) 06:55:23 (i.e. 
58 s after burst trigger) in robotic mode. Series of 30 s  exposures 
were obtained in clear filter.  After PSF subtraction of a nearby bright 
star we clearly detect the optical transient in each single  frames of 
initial series. Coordinates of the optical transient are (J2000) 16 52 
53.29 +82 03 15.6 with uncertainty of 0.25" in both coordinates. 
Preliminary photometry  is based  on USNO-B1.0 (R2)  stars. The maximum 
brightness of the OT (15.2  +/-  0.05) was detected in the second frame 
at 0.00141 days after trigger.

Light curve of the initial stage of the OT can be found at
http://grb.rssi.ru/GRB131002A/GRB131002A_ISON-NM_lc.png