TITLE:   GCN CIRCULAR
NUMBER:  36384
SUBJECT: GRB 240502A: GOTO optical upper limit
DATE:    24/05/03 14:58:26 GMT
FROM:    Amit Kumar at University of Warwick, UK <amitkundu515@gmail.com>

K. Ackley, A. Kumar, B. Godson, G. Ramsay, B. P. Gompertz, R. Starling, M. J. Dyer, J. Lyman, K. Ulaczyk, F. Jimenez-Ibarra, D. O'Neill, D. Steeghs, D. K. Galloway, V. Dhillon, P. O'Brien, K. Noysena, R. Kotak, R. P. Breton, L. K. Nuttall, E. Pall'e and D. Pollacco report on behalf of the GOTO collaboration:

The Gravitational-wave Optical Transient Observer (GOTO, Steeghs et al. 2022) performed a targeted observation in response to Fermi GBM detected GRB 240502A (Fermi GBM Team, GCN 36368) at 2024-05-02 UT 21:10:27 (at 15.69 hours after trigger). Each set of observations consisted of 4x90s exposures in the GOTO L-band (400-700 nm).

Images were processed immediately after acquisition using the GOTO pipeline. No optical counterpart is detected within the INTEGRAL uncertainty circle (Mereghetti et al. GCN 36369) up to the 5-sigma limit of L > 20.1 mag (AB).

Calibration was performed using ATLAS-REFCAT2 (Tonry et al. 2018) and the magnitude is 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).