GCN Circular 22652
Subject
GRB 180418A: RATIR Optical Observations
Date
2018-04-18T12:45:53Z (6 years ago)
From
Eleonora Troja at GSFC <eleonora.troja@nasa.gov>
Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM),
Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),
Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and
Vicki Toy (UMD) report:
We observed the field of GRB 180418A (D'Elia, et al., GCN 22646) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on
Sierra San Pedro M��rtir from 2018/04 18.28 to 2018/04 18.43 UTC
(1.8 minutes to 3.64 hours after the BAT trigger), obtaining a total of
2.57 hours exposure in the r and i bands.
At the position of the optical afterglow (Zheng & Filippenko, GCN 22647),
in comparison with the SDSS DR9 catalog, we obtain the following
detection:
�� r������ = 19.95 +/- 0.01
This magnitude is in the AB system and is not corrected for Galactic
extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
Further observations are planned.