[vsnet-grb-info 27102] GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29205
SUBJECT: GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
DATE:    20/12/30 11:31:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

N. Pankov (IKI, HSE), A. Pozanenko (IKI), R. Ya. Inasaridze (AbAO), I. 
Reva (FAI), V. R. Ayvazian (AbAO),  G. V. Kapanadze (AbAO),  S. Belkin 
(IKI)  report on behalf of IKI-GRB-FuN:

We observed the field of  GRB 201229A (Sbarufatti et al., GCN 29192) 
with AS-32 telescope of Abastumani observatory (AbAO), and Zeiss-1000 
telescope of TSHAO in R-filter. We detected the optical object at the 
edge of enhanced XRT position (Osborne et al., GCN 29193). An optical 
afterglow candidate  (Sbarufatti et al., GCN 29192; Moskvitin at al., 
GCN 29204) is detected in AbAO observations and not detected in   TSHAO 
observations with shallow upper limit. Coordinates of the optical object 
  (J2000) 14:02:45.36 +48:11:53.5 with uncertainty of 0.3 arcsec (in 
both coordinates) are  consistent with coordinates reported by UVOT 
(Sbarufatti et al., GCN 29192) and SAO RAS  (Moskvitin at al., GCN 
29204). Preliminary photometry of the object is following

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

2020-12-29  20:38:18   0.42095  R    23*120  n/d   n/d  20.2  Zeiss-1000
2020-12-30  01:52:12   0.64354  R    68*60   21.1  0.2  21.3  AS-32


The photometry is based on SDSS DR12 star (Lupton transformations)

RA         DEC       R(Lupton)
210.720000 48.157954 18.28

The non-detection of the object by Zeiss-1000 is consistent with 
Nanshan/NEXT optical upper limit (Fu et al., GCN 29203).

The object is absent in SDSS DR12 and we confirm the afterglow of GRB 
201229A.