GCN Circular 37943
Subject
GRB 241029A: GOTO optical afterglow detection
Date
2024-10-29T17:15:04Z (15 days ago)
From
kendall.ackley@warwick.ac.uk
Via
Web form
K. Ackley, B. P. Gompertz, A. Kumar, D. O'Neill, R. Starling, M. J. Dyer, J. Lyman, K. Ulaczyk, F. Jimenez-Ibarra, 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:
We report on observations with the Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022, Dyer et al. 2024) in response to GRB 241029A, detected by Fermi/GBM (Fermi GBM team, GCN 37932), SVOM/ECLAIRs (Schanne et al., GCN 37934) and SVOM/GRM (Wang et al., GCN 37935). Observations were performed by GOTO-S between 09:46:21 and 12:06:59 UT on 2024-10-29 (starting 7.34 hours after trigger). Each observation consisted of 4x90s 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 pointings. We detect the reported optical afterglow, originally discovered by TRT (Jiang et al., GCN 37937) and confirmed by Mephisto (Lin et al., GCN 37939), Xinglong-2.16m (Jiang et al., GCN 37940) and MASTER (Francile et al., GCN 37941). We obtained the following 3-sigma detections and limits of the optical counterpart:
Date | T-T0 (d) | Filter | Mag
-----------------------------------------------------------------------
2024-10-29 09:49:05 | 0.312 | L | 20.59 ± 0.3
2024-10-29 10:55:41 | 0.358 | L | 20.62 ± 0.4
2024-10-29 12:03:21 | 0.405 | L | >20.43
Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction.
Observations are ongoing.
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).