Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 20609

GRB 170205A: RATIR Optical and NIR Observations
2017-02-05T19:35:56Z (7 years ago)
Nat Butler at Az State U <>
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), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jes��s
Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy
(UMD) report:

We observed the field of GRB 170205A (Troja, et al., GCN 20603) with the
Reionization and Transients Infrared Camera (RATIR; on the
1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on
Sierra San Pedro M��rtir from 2017/02 5.53 to 2017/02 5.58 UTC (2.3 minutes
to 1.25 hours after the BAT trigger), obtaining a total of 0.61 hours
exposure in the r and i bands and 0.29 hours exposure in the Z and Y bands.

In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following
detections for the optical afterglow (see, also, Guidorzi, et al., GCN

r = 18.31 +/- 0.01
i = 17.90 +/- 0.01
Z = 18.06 +/- 0.01
Y = 19.26 +/- 0.07

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The source fades (from i~16 mag)
as t^(-1.6) until ~15 minutes after the GRB, after which the fade flattens
to t^(-1.1).

We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
Looking for U.S. government information and services? Visit