[vsnet-grb-info 19733] GRB 170822A: AbAO optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21654
SUBJECT: GRB 170822A: AbAO optical upper limit
DATE:    17/08/23 13:14:20 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Mazaeva (IKI),  R. Inasaridze (AbAO), A. Pozanenko (IKI),   A. 
Volnova  (IKI),   V. Ayvazian (AbAO),  O. Kvaratskhelia (AbAO), G. 
Inasaridze (AbAO), I. Molotov (KIAM) report on behalf of larger GRB 
follow-up  collaboration:

We observed the field of the Swift  GRB 170822A   (Melandri et al.,
GCN  21640)) with AS-32 (0.7m) telescope of Abastumani Observatory 
starting on August, 22 (UT) 22:43:12. We obtained several unfiltered 
images of the field.   Within enhanced XRT error circle  (Beardmore et 
al., GCN   21643) we do not detect  the afterglow candidate (Tello et 
al, GCN 21642). Preliminary photometry of the field is following

Date        UT start  t-T0     Filter Exp.   OT   Err UpLim (3 sigma)
                       (mid, days)     (s)

2017-08-22 22:43:12  0.58255   CR     32*60  n/d  n/d 22.2

Photometry is based on nearby USNO-B1.0 stars R2 magnitudes
USNO-B.1_id  R2
1450-0165651 15.44
1450-0165657 15.54
1450-0165669 16.19
1450-0165558 16.58
1450-0165549 15.60
1450-0165573 15.28
1449-0164981 16.05

A finding chart can be found at 
http://grb.rssi.ru/GRB170822A/GRB170822A_AAO_170822+Bootes-OT.png