GCN Circular 18153
Subject
GRB 150817A: P60 Observations
Event
Date
2015-08-18T13:30:21Z (11 years ago)
From
S. Bradley Cenko at NASA/GSFC <brad.cenko@nasa.gov>
S. B. Cenko (NASA/GSFC) and D. A. Perley (DARK) report on behalf of a larger collaboration:
We observed the location of GRB150817A (D�Elia et al., GCN 18143) with the robotic Palomar 60 inch telescope (P60). Observations began at 3:35 UT on 2015 Aug 17 (~ 90 min after the Swift trigger time). We detect a faint source at the location of the (second) candidate optical afterglow from RATIR (Butler et al., GCN 18145). Using nearby point sources from the APASS survey, we measure an i-band magnitude of 21.42 +/- 0.11 in a stacked frame at a median epoch of dt = 125 min after the Swift trigger.