[vsnet-grb-info 5103] GRB 070920B: NOT optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6809
SUBJECT: GRB 070920B: NOT optical observations
DATE:    07/09/21 10:54:32 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte at iaa.es>

A. de Ugarte Postigo, J. Gorosabel, M. Jelinek,
A.J. Castro-Tirado (IAA-CSIC, Granada),
D. Perez-Ramirez (U. Jaen), R. Corradi (ING, La Palma),
T. Liimets (ING, La Palma and Tartuu Obs.) report:

We have observed the field of GRB070920B (Racusin et al.,
GCNC 6808) using the 2.5m NOT telescope (+ALFOSC) at
Roque de los Muchachos Observatory in V, R and I bands
(180 s each) at high airmass. The mean time of the
observations was 21.0486 Sep. 2007 (UT), ~4.1 hours after
the burst.  We do not detect any bright afterglow candidate
within the Swift/BAT error box.
However, we do see a red, stationary object (detected in R
and I bands) slightly over the DSS2 limit that does not seem
to have its correspondent in the DSS2 images. The
coordinates of this object are (J2000 +/- 0.5"):

R.A.: 00:00:34.56
Dec.: -34:49:08.4

Further observations are needed to confirm wether this could
be the optical afterglow of GRB 070920B.

A finding chart comparing with the DSS2 can be found at:

www.iaa.es/~deugarte/GRBs/070920B/GRB070920B.jpg

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