TITLE:   GCN CIRCULAR
NUMBER:  22298
SUBJECT: GRB 180102A: NOT optical observations
DATE:    18/01/03 08:20:40 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), K. E. Heintz (Univ. Iceland and DARK/NBI), A. 
Sagues Carracedo (NOT), Andreas Kjaer Dideriksen (Aarhus Univ.), report 
on behalf of a larger collaboration:

We observed the field of GRB 180102A (Page et al., GCN 22292; Veres, GCN 
22295) with the Nordic Optical Telescope (NOT) equipped with the AlFOSC 
camera. Observations were carried out in the SDSS r and z filters (900 
and 1000 s exposure, respectively), with a seeing of 1.5", and started 
on 2018 Jan 3.1769 UT (12.42 hr after the GRB trigger).

At the position of the X-ray counterpart (D'Ai et al., GCN 22296), no 
objects are detected down to (preliminary) limiting magnitudes r = 22.5, 
z = 22.0 (all AB, calibrated with reference to nearby Pan-STARRS stars).