TITLE:   GCN CIRCULAR
NUMBER:  13054
SUBJECT: GRB 120312A: NOT observations
DATE:    12/03/13 04:42:24 GMT
FROM:    Paul Vreeswijk at U of Iceland  <pmv@raunvis.hi.is>

Paul Vreeswijk (U. Iceland), Dong Xu (WIS), John Telting, Gintaras
Barisevicius (NOT), Daniele Malesani (DARK/NBI), Páll Jakobsson
(U. Iceland) report on behalf of a larger collaboration:

Using ALFOSC on the Nordic Optical Telescope (NOT) we have obtained
r'- (3 x 300 s) and z'-band (6 x 300 s) imaging of the field of the Swift
GRB 120312A (Stamatikos et al., GCN 13049; Barthelmy et al., GCN
12052), starting on 2012 March 13.085 UT (9.93 hr after the GRB). The
seeing during the observations was around 1".

We do not detect any object within the enhanced Swift-XRT error circle
(Mangano et al., GCN 13053) down to approximate limiting magnitudes of
r'>23.5 and z'>22.2 (calibrated against the SDSS catalog).