[vsnet-grb-info 24771] GRB 200122A: Optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26870
SUBJECT: GRB 200122A: Optical upper limit
DATE:    20/01/24 14:50:35 GMT
FROM:    Dimple Panchal at ARIES, India  <dimple at aries.res.in>

Dimple, R. Gupta, V.K. Jha, A. Aryan, A. Ghosh, K. Misra, A. Kumar, and S.B. Pandey report: 

We carried out observation of GRB 200122A (Sonbas et al., GCN Circ. 26844) with the 1.3m Devasthal Fast Optical Telescope (DFOT) at Devasthal observatory of Aryabhatta Research Institute of observational sciencES (ARIES), India. 
The observation was started on 2020-01-23 at 10:29:41 UT. We observed a series of 3 x 300s exposures using R filter (Johnson-Cousins) covering Swift XRT enhanced position RA, Dec = 210.01807,+2754884 (Osborne et al., GCN Circ. 26846). 

We do not detect any new optical source within the Swift XRT enhanced error circle neither in single images nor in the combined image. 

We obtained the 3-sigma upper limit as follows 

T_start-T0 (hours) Start_UT End_UT Filter 3-sigma upper limit 
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8.8 10:29:41 10:44:41 R >21.13 
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Photometry is done based on USNO-B1.0 catalog. This magnitude is not corrected for Galactic extinction in the direction of the GRB.