[vsnet-grb-info 13425] GRB 130604A: further ISON-NM optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14758
SUBJECT: GRB 130604A: further ISON-NM optical observation
DATE:    13/06/04 11:11:35 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

L. Elenin (KIAM),  V. Savanevych (KNURE),  A. Bryukhovetskiy (NSFCTC),  I. 
Molotov (KIAM), A. Pozanenko (IKI) report on behalf of  larger GRB follow-up 
collaboration:

After further inspection of images after observation of the Swift GRB 
130604A (Melandri et al., GCN 14752)  with 0.45-m telescope of ISON-NM 
(Elenin, et al., GCN 14756) we identified faint object (S/N ~ 3) in 
coordinates (J2000) 16 40 45.34   +68 13 34.5  with uncertainty of  0.2" (in 
both coordinates). Within errors this position coincides with the afterglow 
candidate (Perley, GCB 14753) and the error circle of XRT reported by 
Melandri et al. (GCN 14752). This object is not detected in our later 
combined images and can be the afterglow of GRB 130604A. Preliminary 
photometry  of our images obtained in clear filter is based  on USNO-B1.0 
(R2)  nearby  stars:

UT start,      T0+          Exposure,  OT,                 UL (3 sigma)
                   mid,days  s

06:56:11       0.0019    3x30           n/d                  19.7
06:56:11       0.0035    9x30           20.3 +/- 0.3      20.0
06:56:11       0.0091  30x30           n/d                  20.5
06:56:11       0.0171  60x30           n/d                  20.8

Finding chart can be found at 
http://grb.rssi.ru/GRB130604A/GRB130604A_ISON_NM_9x30.png