GCN Circular 23098
Subject
GRB 180806A: NOT optical observations
Date
2018-08-08T02:13:55Z (6 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
Daniele Bj��rn Malesani (DAWN/NBI and DARK/NBI) and Ana Sagues (NOT) report:
We observed the candidate optical counterpart (Lipunov et al., GCN
23091; Watson et al., GCN 23092) of the Fermi GRB 180806A (Malacaria et
al., GCN 23095) using the Nordic Optical Telescope (NOT) equipped with
the AlFOSC camera.
In a single 300 s exposure centered on 2018 Aug 8.07 UT (27.09 hr after
the GRB), we detect the candidate afterglow with a magnitude r = 22.31
+- 0.10 AB, calibrated against nearby stars from the Pan-STARRS catalog.
The continued fading compared to previous reports (Lipunov et al., GCN
23091; Butler et al., GCN 23094; Watson et al., GCN 23096), as well as
the spatial coincidence with an X-ray source (Gibson et al., GCN 23097)
confirm the interpretation of this source as the optical afterglow of
GRB 180806A.