TITLE:   GCN CIRCULAR
NUMBER:  39685
SUBJECT: GRB 241213A: VIRT Optical Upper Limit
DATE:    25/03/12 13:11:33 GMT
FROM:    Priya Gokuldass at ERAU <gokuldap@my.erau.edu>

K. Smith (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), B. Gendre (UVI), D. Morris (NASA), T. Lombardi (Eckerd College), F. George (ERAU), D. Smith (UVI), R. Querrard (UVI), and C. Watson (UVI) report:

We observed the field of GRB241213A (Gupta et al., GCN 38547) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 2024-12-14 starting at 7:34:05 UT (T-mid ~ T0 + 20.3 hrs). We performed a series of exposures in an R filter with a total exposure of 740s. The weather conditions were partly cloudy during the hours of observation with an average airmass of 1.1. 

We do not detect any source within the enhanced XRT position (Osborne et al. GCN 38552). This non-detection is consistent with reported detections (Qiu et al., GCN 38566) and upper limits  (Spiridonova et al., GCN 38550; Shilling et al., GCN 38564; Brivio et al., GCN 38553; Strausbaugh et al., GCN 38558; and Qiu et al., GCN 38566). We report the following 3-sigma upper limit:

T_mid                ||Exposure   ||Filter   ||Limit 
T+20.3 h             || 740 s     || R       || > 20.3

The limit is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. 

We acknowledge financial support from NASA EPSCoR award 80NNSC22M0063, NSF PAARE award 2319415, and NASA EPSCoR award 80NSSC24M0112. This message can be cited.