TITLE:   GCN CIRCULAR
NUMBER:  16976
SUBJECT: GRB 141020A: Continued Mondy Observations, optical upper limit
DATE:    14/10/29 00:06:16 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), E. Klunko (ISTP),  A. Volnova (IKI), M. Eselevich 
(ISTP), I. Korobtsev (ISTP), A. Pozanenko (IKI) report on behalf of 
larger GRB follow-up collaboration:

We observed the field of the Swift GRB 141020A  (Cenko et al., GCN 
16928) with with AZT-33IK telescope of Sayan observatory (Mondy). We 
obtained several images on Oct. 23 starting on (UT) 14:25:05.  At the 
position of optical afterglow (Cenko et al., GCN 16928; Kuin et al., GCN 
16932; Mazaeva et al., GCN 16943) we do not detect any object down to 
R=23.0. Preliminary photometry is following:

date        UT start  t-T0     Filter  Exp.    OT   OT_UL (3 sigma)
                       (mid, days)          (s)

2014-10-23  14:25:05  3.3309     R     80*120  n/d  23.0

The photometry is based on SDSS stars reported in GCN 16943.