GCN Circular 44727

Subject

EP260527a/GRB 260527A: Infrared J upper limit with MDM/MIRAGE

Event

EP260527a

Date

2026-05-28T22:59:26Z (21 hours ago)

From

Geoffrey Mo at Caltech / Carnegie Observatories <gmo@mit.edu>

Via

Web form

Geoffrey Mo (Carnegie/Caltech), K. De, V. Karambelkar, S. Ibrahim, D. Schiminovich (Columbia University) report:

We observed the field of EP260527a/GRB 260527A (Yang et al., GCN 44718

; Svinkin et al., GCN ; Yu et al., GCN ; Yang et al., GCN ; Kawakubo et al., GCN ) in the near-infrared J band with the MDM InfraRed Astronomy inGaas Experiment (MIRAGE) camera on the MDM 1.3 m telescope.

Observations began at 2026-05-28T05:00:58 (+23 hours after the EP trigger) in the J band, lasting 600 s under cloudy conditions.

We do not detect the optical counterpart (Aguilar-Ruiz et al., GCN 44719

; Li et al., GCN ), with the following 5-sigma upper limit: J > 18.4 mag AB.

MIRAGE is a new YJHs-band near-infrared imager for the MDM 1.3m telescope. We thank the MDM Observatory staff for supporting the observations.