Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 23421

GRB 181110A: VLT/X-shooter redshift
2018-11-11T12:05:33Z (6 years ago)
Daniel Perley at Liverpool JMU <>
D. A. Perley (LJMU), D. B. Malesani (DAWN/NBI and DARK/NBI), J. P. U.
Fynbo (DAWN/NBI and DAWN/DTU), K. E. Heintz (Univ. Iceland), D. A. Kann
(HETH/IAA-CSIC), V. D'Elia (SSDC), L. Izzo (HETH/IAA-CSIC), and N. R.
Tanvir (Univ. Leicester) report:

We observed the optical counterpart of GRB 181110A (Evans et al. GCN
23413; Yamanaka et al., GCN 23414; Murata et al. GCN 23415) with the
ESO-VLT UT2 equipped with the X-shooter spectrograph.  We acquired four
600 second spectra on UT 2018-11-11 between 00:36 and 01:21,
approximately 16 hours after the GRB.  The optical afterglow was R~20.4
at this time.

Continuum is detected in the reduced spectrum across the entire spectral
range of the instrument (blue limit of 3000 Angstroms).  Several weak
absorption features are also detected: in particular, we identify Mg II
and Fe II at a common redshift of z=1.505, identifying this as the most
likely redshift of the GRB.  An additional intervening system is also
identified from (probable) Mg II absorption at z=0.28.

We acknowledge the ESO observing staff at Paranal, including Stephane
Brillant and Eleonora Sani.
Looking for U.S. government information and services? Visit