GCN Circular 29274
We observed the field of GRB210104A (The Fermi GBM team, GCN 29232, Troja et al., GCN 29233) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 01-05-2021 starting at 23:44:00 UT with a midpoint of observation of T+40 hrs. We performed a series of exposures in R filter with a total exposure of ~10ks. The weather conditions were clear during the hours of observation with an average airmass of 1.7. We detect a source consistent with the UVOT position (Troja et al., GCN 29233) and optical transient identified by others (e.g., Bilitzinger et al., GCN 29234, Xin et al., GCN 29235, Hu et al., GCN 29236) with magnitude: R= 20.8 +/- 0.3 This magnitude is consistent with the powerlaw decay rate of alpha = 0.73 reported by Zhu et al, GCN 29252. The magnitude is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. Further analysis is in progress. The VIRT is still in the commissioning phase. This work is supported by NASA-MUREP-MIRO grant NNX15AP95A, NSF EiR AST Award 1901296, and NSF HBCU-UP AST Award 1831682. This message can be cited.