[vsnet-grb-info 27205] ZTF21aaeyldq: observations with the 3.6m Devasthal Optical Telescope

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29308
SUBJECT: ZTF21aaeyldq: observations with the 3.6m Devasthal Optical Telescope
DATE:    21/01/17 10:13:28 GMT
FROM:    Amit Kumar at ARIES, India  <amitkundu515 at gmail.com>

Amit Kumar (ARIES), Shashi B. Pandey (ARIES), Rahul Gupta (ARIES), Dimple
(ARIES), Ankur Ghosh (ARIES), Amar Aryan (ARIES), Brajesh Kumar (ARIES),
and Kuntal Misra (ARIES) report:

We observed the ZTF discovered fast-fading hostless transient ZTF21aaeyldq
(Ho et al., GCN 29305) using the 4Kx4K CCD Imager (Pandey et al. 2018,
2018BSRSL..87...42P) mounted at the axial port of the 3.6m Devasthal
Optical Telescope of ARIES Nainital. The transient has been identified as a
GRB afterglow at z = 2.514 by Postigo et al. GCN 29307.

The observations were started on 2021-01-16 at 22:15:12.980 UT (~15.258
hours after the detection). We observed two images with an exposure time of
300 seconds each in Bessel R and I bands. At the position reported by Ho et
al., GCN 29305, we detect an uncatalogued source in both R and I bands.

The observed R-band magnitude is as follows:

Date                UT start        T-T0 (hours)     Exp.     Filter  OT
(mag)  Err
------------------------------------------------------------------------------------------------

2021-01-16     22:15:12.980   15.258           1*300       R       21.04
  0.06

The quoted magnitude is calibrated with the nearby USNO-B1 stars and not
corrected for the Galactic and Host extinction in the direction of the
burst.

3.6m Devasthal Optical Telescope (DOT) is a recently commissioned facility
in the Northern Himalayan region of India (long:79 41 04E, lat:29 21 40N,
alt:2540m) owned and operated by the Aryabhatta Research Institute of
Observational Sciences (ARIES), Nainital (https://www.aries.res.in).
Authors of this GCN circular thankfully acknowledge consistent support from
the technical staff members to run and maintain the 3.6m DOT.

This circular may be cited.