GCN Circular 20886
Subject
GRB 170317A: ISON-Ussuriysk aferglow confirmation
Event
Date
2017-03-17T13:06:50Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Pozanenko (IKI), A. Kochergin (UAFO), A. Volnova
(IKI), E. Chornaya (UAFO), A. Matkin (UAFO, ISON), I. Molotov
(KIAM) report on behalf of larger GRB follow-up collaboration:
We observed the field of the GRB 170317A (LaPorte et al., GCN 20885)
with SANTEL-650 (0.65m) telescope of UAFO/ISON-Ussuriysk observatory
starting on March, 17 (UT) 10:20:37. We obtained series of unfiltered
images of 60 s exposure. In a first combined images we detected optical
afterglow (LaPorte et al., GCN 20885). Preliminary photometry of some
initial combined image is following
Date UT start t-T0 Filter Exp. OT err UL (3sigma)
(mid, days) (s)
2017-03-17 10:20:37 0.0321 none 20*60 18.95 0.08 21.5
In comparison with early reported photometry (LaPorte et al., GCN
20885) the OT is faded, and we confirm the afterglow of the GRB 170317A.
Photometry is based on nearby USNO-B1.0 stars
USNO_B1_id R2
1405-0167482 15.08
1405-0167474 15.43
1405-0167493 16.10
1405-0167484 16.14
1404-0169177 15.93
1405-0167639 15.62
1405-0167631 15.69