[vsnet-grb-info 10607] GRB 110521A - NOT optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12036
SUBJECT: GRB 110521A - NOT optical observation
DATE:    11/05/22 00:54:55 GMT
FROM:    Steve Schulse at U. of Iceland  <steve at raunvis.hi.is>

S. Schulze (U. Iceland), D. Xu (WIS), P. Jakobsson (U. Iceland), T.
Pursimo (NOT Observatory), report on behalf of a larger collaboration:

We observed the field of GRB 110521A (Oates et al., GCN 12031) with
the Nordic Opitcal Telescope (NOT) equipped with ALFOSC. We obtained
3x300 s R-band and 6x300 s I-band images. Observations started at
22:01 UT on May 21 (i.e., 6.1604 hrs after the burst).

We do not detect any source in the stacked R-band and I-band images at
the refined XRT position (Beardmore et al., GCN 12034).

The limiting magnitudes are R ~ 24.4 mag at the mid-exposure time
t = 6.285 hrs post-burst, and I ~ 23.8 mag at the mid-exposure time
t = 6.745 hrs post-burst, calibrated with the #1358-0196725 star
(R1 = 19.57, R2 = 19.58, and I =18.81) in the USNO B1 catalogue.