TITLE: GCN CIRCULAR NUMBER: 37416 SUBJECT: GRB 240905E: J-band observations with WINTER DATE: 24/09/06 22:35:04 GMT FROM: Geoffrey Mo at MIT <gmo@mit.edu> Geoffrey Mo (MIT), Tomas Ahumada (Caltech), Benjamin Schneider (MIT), Viraj Karambelkar (Caltech), Danielle Frostig (CfA), Robert Stein (Caltech), Nathan Lourie (MIT), Robert Simcoe (MIT), and Mansi Kasliwal (Caltech) report: We observed the field of GRB 240905E (Dichiara et al., GCN 37397; Zhang et al., GCN 37404) in the near-infrared J-band with the Palomar 1-m telescope, equipped with the 1 square degree WINTER camera (Lourie et al. 2020). Observations began at 2024-09-06T02:54:16 UTC (~8.5 hours after the GRB) and consisted of 15 x 120 s exposures. The images were processed using the WINTER data reduction pipeline (https://github.com/winter-telescope/mirar). We do not detect any sources within the refined Swift/XRT error circle (Ferro et al., GCN 37406), consistent with observations reported by other groups (Lipunov et al., GCN 37398; An et al., GCN 37399; Moskvitin et al., GCN 37401; Shilling et al., GCN 37402; Strausbaugh et al., GCN 37403; Brivio et al., GCN 37408; Fu et al., GCN 37409; Adami et al., GCN 37412; Wu et al., GCN 37413; Odeh et al., GCN 37414; Belkin et al., GCN 37415). We also do not detect a source at the position of the potential CrAO OT candidate (Belkin et al., GCN 37415). We obtain the following 5-sigma upper limit: J ~ 18.6 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 Lucille Packard Foundation, and the MIT Kavli Institute for Astrophysics and Space Research. View this GCN Circular online at https://gcn.nasa.gov/circulars/37416. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...