TITLE:   GCN CIRCULAR
NUMBER:  22193
SUBJECT: GRB 171205A: CHILESCOPE optical observations
DATE:    17/12/06 20:57:10 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), A. Pozanenko (IKI),  E. Mazaeva (IKI),  M. Krugov 
(AFIF) report on behalf of IKI-GW follow-up collaboration:

We observed the field of GRB 171205A (D'Elia et al., GCN 22177)   with 
RC-1000 1m telescope of CHILESCOPE observatory. The observations carried 
out in a clear filter starting on Dec. 06 (UT) 06:46:47. The afterglow 
of GRB 171205A (e.g.  Osborne et al., GCN 22179;  Izzo et al., GCN 
22180; Emery et al., GCN 22181) is clearly detected.  Preliminary 
photometry is following.

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

2017-12-06 06:46:47  1.00122  CR     3600    18.20  0.07


The photometry is based on several nearby USNO-B1.0 stars (R2 magnitudes).

USNO-B1.0      RA          Dec         R2
0774-0291882  11:09:46.28 -12:35:02.8  17.25
0773-0296803  11:09:34.42 -12:37:07.2  16.58
0774-0291827  11:09:37.14 -12:32:33.8  16.45
0774-0291826  11:09:36.63 -12:34:12.4  16.40
0774-0291864  11:09:43.12 -12:33:49.8  16.30
0774-0291938  11:09:56.38 -12:35:37.7  16.40
0773-0296901  11:09:57.46 -12:36:29.0  15.34

Finding chart can be found at
http://grb.rssi.ru/GRB171205A/GRB171205_RC1000-171206.png