[vsnet-grb-info 14108] GRB 131031A: 1.23m CAHA I-band and 1.5m OSN R-band observations of Swift/BAT error circle

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15422
SUBJECT: GRB 131031A: 1.23m CAHA I-band and 1.5m OSN R-band observations of Swift/BAT error circle
DATE:    13/10/31 23:28:53 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu at iaa.es>

V. Terron (IAA-CSIC), J. Gorosabel (IAA-CSIC,UPV/EHU), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), A.J. Castro-Tirado (IAA-CSIC), A. Sota (IAA-CSIC), report on behalf of a larger collaboration:

We imaged the field of the GRB131031A (Cummings GCN 15421) with the 1.23m CAHA telescope. The observations were carried out at 21:24--22:04 UT (mean epoch 10.2 hours post burst) in the I-band with a total exposure time of 7x300s. Visual comparison with the SDSS did not reveal new objects brighter than I~20.5 (Vega) within the BAT error circle.  A contemporaneous 900s R-band image taken with the 1.5m OSN telescope did not reveal any new object either brighter than R>19.5 (Vega).