GCN Circular 28785
Subject
GRB 201026A: NOT optical upper limits
Date
2020-10-27T00:31:29Z (4 years ago)
From
Daniele B Malesani at DTU Space <malesani@space.dtu.dk>
L. Izzo (DARK/NBI), D. B. Malesani (DTU Space), T. Kuutma (NOT), report
on behalf od a larger collaboration:
We observed the optical afterglow of GRB 201026A (Cenko et al., GCN
28784) using the Nordic Optical Telescope (NOT) equipped with the ALFOSC
imaging camera. A set of 2x300 s and 5x200 s images was secured in the
SDSS r and z bands, respectively. The mid time of the observation was
Oct 26.968 (36.2 min after the GRB). Observations were conducted at high
airmass under moderate seeing conditions (1.4").
No new object is detected consistent with the XRT position, down to a
limiting magnitude r= 21.5, z = 21.4 AB (3 sigma), calibrated against
nearby stars from the Pan-STARRS catalog.
We note the presence of a faint, possibly extended object visible in the
archival Pan-STARRS images, at a position consistent (RA = 13:06:58.71,
Dec = +83:46:58.5) with that of the X-ray afterglow. This object could
be the host galaxy of GRB 201026A, but we caution that the currently
available uncertainty radius of the XRT position is still relatively
large (3.9"), hence the association not robust.