TITLE: GCN CIRCULAR NUMBER: 38066 SUBJECT: EP241103a: GOTO optical upper limit DATE: 24/11/03 20:09:50 GMT FROM: Ben Gompertz at U of Birmingham <b.gompertz@bham.ac.uk> B. P. Gompertz, A. Kumar, G. Ramsay, D. O'Neill, R. Starling, K. Ackley, M. J. Dyer, J. Lyman, K. Ulaczyk, F. Jimenez-Ibarra, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Palle and D. Pollacco report on behalf of the GOTO collaboration: We report on observations of EP241103a (Zhao et al., GCN 38051) with the Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022, Dyer et al. 2024). The position of the X-ray counterpart detected by EP/FXT (Zhao et al., GCN 38058) and Swift/XRT (Jonker et al., GCN 38063) was serendipitously covered by GOTO-N in survey mode at 02:03:32 UT on 2024-11-03, 39 minutes after trigger. The observation consisted of 4x45s exposures in the GOTO L-band (400-700 nm). No new optical source is detected to a 3-sigma limit of L > 20.2 mags (AB). Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction. GOTO (https://goto-observatory.org) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC). View this GCN Circular online at https://gcn.nasa.gov/circulars/38066. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...