GCN Circular 37486
Subject
GRB 240911A: GOTO optical limits on Swift/XRT candidates
Event
Date
2024-09-13T13:17:21Z (2 years ago)
From
Amit Kumar at University of Warwick, UK <amitkundu515@gmail.com>
Via
Web form
A. Kumar, Y. Julakanti, B. P. Gompertz, J. Lyman, R. Starling, K. Ackley, M. J. Dyer, K. Ulaczyk, F. Jimenez-Ibarra, D. O'Neill, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, G. Ramsay, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Palle and D. Pollacco report on behalf of the GOTO collaboration:
The Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022) serendipitously covered part of the localisation region of the SVOM/ECLAIRs-detected and Swift/XRT followed-up GRB 240911A (Schanne et al. GCN 37462; Williams et al. GCN 37483) in survey mode at 2024-09-12 04:40:43 UT (8.03 hours after trigger). Each observation consisted of 4x45s exposures in the GOTO L-band (400-700 nm).
Images were processed immediately after acquisition using the GOTO pipeline. Difference imaging was performed using deeper template observations of the same paintings.
No candidate optical counterpart is detected at the positions of the 2 uncatalogued Swift/XRT detected sources (Williams et al. GCN 37483) to a 5-sigma limiting magnitude of L > 19.3.
Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and were 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).