GCN Circular 12894
Subject
GRB 120119A: GRT detection of early afterglow
Event
Date
2012-01-22T02:16:11Z (14 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori.sakamoto-1@nasa.gov>
T. Sakamoto (UMBC/GSFC), D. Donato (ORAU/GSFC), N. Gehrels (GSFC),
T. Okajima (GSFC), Y. Urata (NCU)
We observed the field of GRB 120119A detected by Swift
(trigger #512035; Beardmore et al., GCN Circ. 12859) with the 14-inch
Goddard Robotic Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).
A total 294 images of 5 sec (200 images), 30 sec (60 images) and
60 sec (34 images) exposures were taken in the R filter starting
from January 19 04:06:42 (UT), about 132 seconds after the trigger
(114 seconds after the BAT position notice), and stopped on
January 19 06:07:50 (UT).
We detect the optical afterglow inside the XRT error circle (Beardmore
et al., GCN Circ. 12876) in the stacked image of good quality 5 sec
exposure images (total exposure of 985 sec). The estimated magnitude is
R = 17.24 +- 0.19 mag (start time: 04:06:42, stop time: 04:44:37). We do
not detected the afterglow in the stacked images of 30 sec exposure images
(total exposure of 1560 sec) and 60 sec exposure images (total exposure of
2040 sec). The estimated five sigma upper limits of those stacked images
are ~17.9 mag (start time: 04:44:55, stop time: 05:30:01) and ~18.0 mag
(start time: 05:30:17, stop time: 06:07:50). All the reported magnitudes
are estimated using the USNO-B1 catalog.