VERITAS Observations of GRB 221009A and other Gamma-Ray Bursts

The VERITAS imaging atmospheric Cherenkov telescopes at the Fred Lawrence Whipple Observatory in southern Arizona have been performing rapid follow-up observations of gamma-ray bursts in the very high-energy (>100 GeV) band since 2006. GRB 221009A occurred near the time of the full Moon on a day when VERITAS observations were not scheduled. We report on observations obtained starting on UT 2022-10-11, about 36 hours after the burst — still under challenging bright moonlight conditions — and continuing until about 21 days after the burst. We also present results of a study of nearly one hundred additional GRBs with few arcminute or better localizations having follow-up observations with VERITAS, and we discuss these observations in the context of the X-ray afterglow emission for these bursts.