[vsnet-grb-info 11998] GRB 120624B: NOT optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13387
SUBJECT: GRB 120624B: NOT optical upper limit
DATE:    12/06/25 23:32:09 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.dark at gmail.com>

D. Xu (WIS), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), D. Malesani
(DARK/NBI), D. Gandolfi (ESTEC/ESA), G. Leloudas (OKC, Stockholm)
report on behalf of a larger collaboration:

We observed the Swift/BAT field of GRB 120624B (Gruber et al., GCN
13377; Vianello&  Kocevski, GCN 13379; Sakamoto et al., GCN 13384)
using the 2.5m Nordic Optical Telescope (NOT) equipped with the ALFOSC
camera, at La Palma, Canary Islands. Observations started at 21:26 UT
on 2012-06-25 (i.e., 23.05 hr after the Fermi trigger) and a series of
SDSS r-band frames with a total exposure time of 1250s were obtained,
but were affected by the dusty calima from the Sahara desert.

No new optical source was detected within the refined BAT error circle
down to a 3-sigma limit of r(AB)~21.0.