TITLE: GCN CIRCULAR NUMBER: 12894 SUBJECT: GRB 120119A: GRT detection of early afterglow DATE: 12/01/22 02:16:11 GMT FROM: Takanori Sakamoto at NASA/GSFC 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.