GCN Circular 36864
Subject
GRB 240713A: J-band upper limit from WINTER
Date
2024-07-14T20:51:53Z (5 months ago)
From
Benjamin Schneider at MIT <bschn@mit.edu>
Via
Web form
Benjamin Schneider (MIT), Geoffrey Mo (MIT), Viraj Karambelkar (Caltech), Robert Stein (Caltech), Danielle Frostig (MIT), Nathan Lourie (MIT), Tomas Ahumada (Caltech), Robert Simcoe (MIT), and Mansi Kasliwal (Caltech) report:
We observed the SVOM/ECLAIRs localization region of GRB 240713A (Schanne et al, GCN 36854) and the possible sub-threshold signal of Fermi/GBM (Burns et al., GCN 36856) in the near-infrared J-band with the Palomar 1-m telescope, equipped with the 1-square degree WINTER camera (Lourie et al. 2020).
Our observations began at 2024-07-13T11:34:28 UTC (~9.5 hours after the GRB trigger) and consisted of 22 exposures of 120s before sunrise. The images were processed using the WINTER data reduction pipeline (https://github.com/winter-telescope/mirar, https://doi.org/10.5281/zenodo.10888436), with image subtraction performed relative to J-band images from the UKIRT Hemisphere survey (Dye et al., 2017).
Our observations covered 90% of the SVOM/ECLAIRs error circle and 8/10 of the EP/FXT soft X-ray afterglow candidates (Yang et al., GCN 36859). EP J233039.0+014426 and EP J233017.4+014339 were out of our field of view. In our stacked and subtracted images, we do not detect any new source to a depth of J ~ 19 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.