TITLE:   GCN CIRCULAR
NUMBER:  30201
SUBJECT: GRB 210610B: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
DATE:    21/06/11 15:33:19 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

A. Dutta (IIA), H. Kumar (IITB), D. K. Sahu (IIA), B. Kumar (ARIES), G. C.
Anupama (IIA), V. Bhalerao (IITB), S. Barway (IIA) report on behalf of a
larger Indian collaboration:

We obtained a spectrum of the GRB 210210B detected by Swift-BAT ( K. L.
Page et al., GCN #30170 ), with the HFOSC instrument mounted on the 2-m
Himalayan Chandra Telescope (HCT) at the Indian Astronomical Observatory
(IAO). We obtained a wavelength coverage of 3800 - 8000 angstrom. We took
an 1800 second exposure on 2021 June 10 22:02 (UTC).

The spectrum has a relatively featureless blue continuum with weak
absorption features due to Fe II (rest-frame wavelength 2587, 2600 A), Mg
II (2799 A), Mg I (2853 A) at a redshift of z=1.13. The redshift is
consistent with that reported by Fynbo et al. GCN #30182, Fu et al. GCN
#30188 and A. de Ugarte Postigo et al. GCN #30194. The spectrum has not
been corrected for reddening.

We thank the staff at IAO and CREST, Hosakote, for helping with the
observations. The Indian Astronomical Observatory and CREST are operated by
the Indian Institute of Astrophysics, Bengaluru, India.