GCN Circular 39684
Subject
GRB 241228A: VIRT Optical Upper Limit
Date
2025-03-12T13:10:18Z (2 days ago)
From
Priya Gokuldass at ERAU <gokuldap@my.erau.edu>
Via
Web form
R. Querrard (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), K. Smith (UVI), C. Watson (UVI) report:
We observed the field of GRB241228A (D'Elia et al., GCN 38681) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 2024-12-28 starting at 03:57:15 UT (T-mid ~ T0 + 43.91 hrs). We performed a series of exposures in an R filter with a total exposure of 2060s. The weather conditions were partly cloudy during the hours of observation with an average airmass of 1.68.
We do not detect any source within the enhanced XRT position (Evans et al. GCN 38683). This non-detection is consistent with reported upper limits (Kuin et al., GCN 38685; Mohan et al., GCN 38689; Lipunov et al., GCN 38693; Zhu et al., GCN 38703; Volnova et al., GCN 38709; and Ror et al., GCN 38815). We report the following 3-sigma upper limit:
T_mid ||Exposure ||Filter ||Limit
T+43.91 h || 2060 s || R || > 20.4
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.