TITLE: GCN CIRCULAR NUMBER: 36686 SUBJECT: GRB 240615A: J-band upper limits from WINTER DATE: 24/06/17 15:22:28 GMT FROM: Viraj Karambelkar at Indian Inst of Tech,Bombay <karambelkarvraj21197@gmail.com> Viraj Karambelkar (Caltech), Geoffrey Mo (MIT), Robert Stein (Caltech), Danielle Frostig (MIT), Tomas Ahumada (Caltech), Nathan Lourie (MIT), Robert Simcoe (MIT), and Mansi Kasliwal (Caltech) report: We observed the Swift-GUANO localization region of short GRB 240615A (GCN 36671, 36672, 36673, 36676, 36680, 36682, 36683) 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 2024-06-16T06:06:34 UTC (~12 hours after the GRB trigger) and lasted for an hour. 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). We do not detect the XRT source (reported by GCN 36683) in our stacked and subtracted images to a depth of J~19 mag (AB). No other new sources are identified in our subtracted images, 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/36686. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...