[vsnet-grb-info 17907] GRB 160425A: SMARTS optical/IR observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19354
SUBJECT: GRB 160425A: SMARTS optical/IR observations
DATE:    16/04/26 20:51:10 GMT
FROM:    Bethany Cobb at GWU  <bcobb at gwu.edu>

B. E. Cobb (GWU), reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained
optical/IR imaging of the error region of GRB 160425A (GCN 19343,
Krimm et al.) at two epochs. For each epoch, total summed exposure times
amounted to 15 minutes in I and V and 12 minutes in J and K.

No source is detected at the position of the optical
afterglow (e.g. GCN 19343, Krimm et al.; GCN 19344, Lipunov
et al.; GCN 19349, Bodensteiner et al.) to the approximate limiting
magnitudes listed below. The first epoch was obtained under particularly
poor seeing conditions.

mid-exposure               mid-exposure time
time                              post-burst
 limits
2016-04-26 04:53 UT  5.44083 hours      I > 19.5   J > 16.6   K > 15.7

2016-04-26 08:29 UT  9.04250 hours      I > 19.9   J > 17.9   K > 17.1

Magnitudes are calibrated using USNO-B1.0 stars in I, and
2MASS stars in J and K.