[vsnet-grb-info 18305] GRB 160801A: NOT upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19753
SUBJECT: GRB 160801A: NOT upper limits
DATE:    16/08/02 11:40:16 GMT
FROM:    Zach Cano at U of Iceland  <zewcano at gmail.com>

Z. Cano (Univ. Iceland), D. Malesani (DARK/NBI and DTU space), J.-K.
Krogager, P. Noterdaeme (IAP) & A. Djupvik (NOT) report on behalf of a
larger collaboration:

We observed the field of GRB 160801A (D'Elia et al.; GCN Circ. 19744) with
the 2.5-m Nordic Optical Telescope equipped with ALFOSC, starting at 21:05
UT on 01 August 2016.  We obtained 14 minutes in the z-band and 10 minutes
in the r-band.  In our co-added images we do not detect any new source(s)
within the enhanced XRT error circle (Goad et al.; GCN Circ. 19746) to the
following limits:

Filter    t-t0 (d)     magnitude limit (AB)
-------------------------------------------
  r       0.50               >24.4
  z       0.49               >23.1

These upper limits are for an isolated point source in the GRB field, they
are calibrated against the SDSS catalogue, and they have not been corrected
for foreground extinction.

We note the presence of an SDSS object (RA = 14:11:03.21, Dec =+13:29:21.5)
just outside the refined XRT error circle. This object is pointlike in our
images (0.8" seeing) and its magnitude did not vary within the errors
compared to the SDSS archival values. We consider it is unlikely that this
object is associated with GRB 160801A.