GCN Circular 22460
Subject
GRB 180305A: RATIR Optical Afterglow Candidate
Date
2018-03-06T11:24:41Z (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 the LAT GRB 180305A (Axelsson, et al., GCN 22457)
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 2018/03 6.11 to 2018/03 6.20 UTC
(17.28 to 19.45 hours after the burst), obtaining a total of 1.36 hours
exposure in the r and i bands.
At the position of source #2 found by Swift-XRT�� (Evans, et al., GCN
22459),
we detect a faint uncatalogued optical source. In comparison with the
USNO-B1 catalog, we obtain the following detections:
�� r������ = 21.95 +/- 0.12
�� i������ = 21.48 +/- 0.08
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
The source is located at RA,Dec = 03:18:28.33,+32:06:36.2 (J2000, +/-0.5").
Further observations to establish fading of the optical source are planned.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.