GCN Circular 19351
Subject
GRB 160425A MASTER notices: possible host galaxy in the optical error-box
Date
2016-04-26T10:45:15Z (8 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
P.Balanutsa, V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, A.Kuznetsov
Lomonosov Moscow State University, Sternberg Astronomical Institute
D.Buckley, S. Potter, A.Kniazev
South African Astronomical Observatory
MASTER-SAAO telescope pointed to the unusual short GRB160425A (Krimm et
al. GCN #19343 ) at 2016-04-25 23:28:59UT 168s after trigger time, 30s first expositions with orthogonal polarimeter filters .
The delay is caused with the short rain, the roof was closed at the trigger time.
MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 280.32738,-54.36004
at the first 30s polarized image in 1 tube at 2016-04-25 23:28:59UT with unfiltered m_OT~18.2+-0.5
(w=0.2B+0.8R calibrated by USNO-B1) http://observ.pereplet.ru/images/MASTERGRB160425A.jpg .
The second tube in orthogonal polarization filter doesn't see it with
m_lim=17.7, possibly it depends on polarization of this source.
There is a faint optical source at the Palomar (POSS) both red and blue images.
But this source doesn't present at USNO-B1 catalogue. There is blue source
(in 0.411") in GSC2.3.2 with jmag=22.16.
The most probable classification of it is the host galaxy of short GRB160425A.
SWIFT UVOT see optical afterglow 19.9m in white filter (150s expos.,
starting 208 seconds after the BAT trigger (23:26:11UT) (Krimm et
al., GCN Circ. 19343) and GROND see afetrglow in g'r'i'z' started at
04:38 UT on April 26, 2016, 5.2 hrs after the GRB (Bodensteiner et al.,
GCN Circ. 19349).
The analyses will be continued.
