GCN Circular 36167
Subject
GRB 240418A: NOT optical upper limits
Date
2024-04-19T00:50:40Z (15 days ago)
From
Daniele B. Malesani at IMAPP / Radboud University <d.malesani@astro.ru.nl>
Via
Web form
D. B. Malesani (DAWN/NBI and Radboud Univ.) and A. C. Casasbuenas (Univ. La Laguna and NOT) report on behalf of a larger collaboration.
We have observed the field of GRB 240418A (Siegel et al., GCN 36162) using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations were carried out under poor sky transparency, and consisted of images in the SDSS r and z bands (mean epochs 3.19 and 3.37 hr after trigger, respectively).
Within or close to the localization error circle of the X-ray afterglow (Evans et al., GCN 36166), we detect no object in either filter, down to limiting AB magnitudes r > 22, z > 20.4, calibrated against nearby stars from the Pan-STARRS catalog.