GCN Circular 44731
Subject
GRB 260527A/EP260527a: Gemini GMOS-S Optical Observations
Event
Date
2026-05-29T02:17:48Z (18 hours ago)
From
Brendan O'Connor at Carnegie Mellon University <boconno2@andrew.cmu.edu>
Via
Web form
Brendan O'Connor (CMU), Malte Busmann (LMU), Julius Gassert (LMU/CMU), Daniel Gruen (LMU), Xander Hall (CMU), and Antonella Palmese (CMU) report:
We observed the counterpart of GRB 260527A/EP260527a (Yang et al., GCN 44718; Aguilar-Ruiz et al., GCN 44719; Li et al., GCN 44720; Svinkin et al., GCN 44722; Yu et al., GCN 44724; Yang et al., GCN 44725; Kawakubo et al., GCN 44726; Mo et al., GCN 44727) using the GMOS-S instrument mounted on the Gemini-South telescope. Our observations were carried out in the r and i filters for 10x90 s exposure in each band.
At the location of the optical counterpart (Aguilar-Ruiz et al., GCN 44719), we detect a source with magnitude i = 23.2 +/- 0.1 AB mag, consistent with recent reports (Busmann et al., GCN 44728; Corcoran et al., GCN 44729; El Kabir et al., GCN 44730). The photometry is calibrated against the PS1 catalog and is not corrected for the minimal Galactic extinction along the line of sight.
We thank the Gemini staff, in particular Aleksandar Cikota, for the rapid scheduling and execution of these observations.