GCN Circular 42105

Subject

GRB 251002A: NIR observations with WINTER

Event

GRB 251002A

Date

2025-10-04T04:03:05Z (a year ago)

Edited On

2025-10-05T16:40:16Z (a year ago)

From

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

Edited By

Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Geoffrey Mo at Caltech / Carnegie Observatories <gmo@mit.edu>

Via

Web form

Geoffrey Mo (Caltech/Carnegie), Tomas Ahumada (Caltech), Viraj Karambelkar (Columbia/CCA), Benjamin Schneider (LAM), Robert Stein (UMD), Danielle Frostig (CfA), Nathan Lourie (MIT), Robert Simcoe (MIT), and Mansi Kasliwal (Caltech) report:

We observed the field of GRB 251002A (Saccardi et al., GCN 42060

; Sun et al., GCN ; Kenya et al., GCN ; Smith et al., GCN ) in the near-infrared J band with the Palomar 1-m telescope, equipped with the 1.2-square degree WINTER camera (Lourie et al. 2020, Frostig et al. 2024).

Observations began at 2025-10-03T03:49:03 UTC in the J band (~7.6 hours after the GRB trigger), consisting of 15 x 120 s exposures. The images were processed using the WINTER data reduction pipeline implemented with mirar (https://github.com/winter-telescope/mirar, https://doi.org/10.5281/zenodo.13352565

We do not detect a source at the optical counterpart location (Palmerio et al., GCN 42061

; Turpin et al., GCN ; Jelinek et al., GCN ; Juliá-Maroto et al., GCN ; Moskvitin et al., GCN ; Perez-Garcia et al., GCN ; Senik et al., GCN ; Saccardi et al., GCN ; Mandarakas et al., GCN ; Cao et al., GCN ; Schneider et al., GCN ; Pankov et al., GCN ; Leonini et al., GCN ; Odeh et al., GCN ; Wortley et al., GCN ; Shilling et al., GCN ; Calapai et al., GCN ). We obtain the following 5-sigma upper limit: J ~ 19.2 mag (AB).

WINTER (Wide-field INfrared Transient ExploreR) is a partnership between MIT and Caltech, housed at Palomar Observatory, and funded by NSF MRI, NSF AAG, the David and Lucile Packard Foundation, and the MIT Kavli Institute for Astrophysics and Space Research.