GCN Circular 22000
Subject
GRB 171010A: NOT optical observations
Date
2017-10-12T01:44:15Z (7 years ago)
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), P.
Calissendorff (Stockholm Univ), and I. R. Losada (NOT) report on behalf
of a larger collaboration:
We observed the optical counterpart (Thorstensen & Halpern, GCN 21987;
Izzo & Malesani, GCN 21988; Guidorzi et al., GCN 21991) of the Fermi GRB
171010A (Poolakkil & Meegan, GCN 21992; Omodei et al., GCN 21985) with
the Nordic Optical Telescope equipped with the StanCam imager.
Observations were carried out in the Johnson-Cousins BVRI filters.
The optical counterpart is well detected in our images. Using the
Pan-STARRS catalog as reference, we measure a magnitude r = 19.18 +-
0.06 AB at an epoch Oct 12.03 UT (29.74 hr after the trigger).
Comparing our measurement with the report by Thorstensen & Halpern (GCN
21987) we infer a decay index alpha = 1.4 assuming an unbroken power-law
decay.