TITLE:   GCN CIRCULAR
NUMBER:  44588
SUBJECT: EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
DATE:    26/05/12 20:43:26 GMT
FROM:    Geoffrey Mo at Caltech / Carnegie Observatories <gmo@mit.edu>

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

We observed the field of EP260507a (Fu et al., GCN 44488, GCN 44500) in the near-infrared J and Hs bands with the MDM InfraRed Astronomy inGaas Explorer (MIRAGE) instrument on the MDM 1.3 m telescope.

Observations began at 2026-05-08T05:49:04 (+16.0 hours after the GRB trigger) in the J band and 2026-05-08T06:22:36 (+16.6 hours) in the Hs band, lasting 1620 s in each filter.

The optical counterpart (Corcoran et al., GCN 44489; Sankar et al., GCN 44490; Jiang et al., GCN 44491; Kumar et al., GCN 44492; Bochenek et al., GCN 44494; Eyles-Ferris et al., GCN 44495; Jiang et al., GCN 44496; Li et al., GCN 44497; Globus et al., GCN 44498; Brivio et al., GCN 44501) is not detected in either band, with the following 5-sigma upper limits in AB magnitudes: J > 19.84, Hs > 19.2.

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.