GCN Circular 20992
Subject
GRB 170405A: ISON/Terskol optical observations
Date
2017-04-06T12:12:17Z (7 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), V. Agletdinov (KIAM), A. Pozanenko (IKI), A. Volnova
(IKI), I. Molotov (KIAM) report on behalf of larger GRB follow-up
collaboration:
We observed the field of GRB 170405A (Troja et al., GCN 20984) with
K-800 (0.8m) telescope of ISON/Terskol observatory starting on
April, 05 (UT) 19:12:55, i.e. 45 minutes after GRB onset. We obtained
several unfiltered images of 15 s exposure. The optical afterglow Troja
et al., GCN 20984; Malesani et al., GCN 20988; Klotz et al., GCN 20989;
Ugarte Postigo et al., GCN 20990; Martin-Carrillo et al., GCN 20991)
is clearly visible in combined images. Preliminary photometry of the
afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2017-04-05 19:12:55 0.03139 CR 72*15 17.27 0.10 20.1
2017-04-05 19:34:33 0.04300 CR 48*15 17.96 0.13 19.8
2017-04-05 19:49:05 0.06019 CR 110*15 18.39 0.14 20.4
2017-04-05 20:23:55 0.08543 CR 110*15 19.18 0.22 20.2
2017-04-05 21:01:48 0.11099 CR 107*15 n/d n/d 18.9
Photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id R2
0647-0315771 15.13
0647-0315754 15.45
0647-0315872 15.34
0647-0315921 15.08
0647-0315788 14.92
Preliminary light curve of the afterglow can be found in
http://grb.rssi.ru/GRB170405A/GRB170405A_light_curve.png
