TITLE:   GCN CIRCULAR
NUMBER:  36084
SUBJECT: GRB 240414A : OHP/T193 optical counterpart detection
DATE:    24/04/14 03:35:59 GMT
FROM:    Christophe Adami at LAM <christophe.adami@lam.fr>

B. Schneider (MIT), C. Adami, O. Ilbert, S. de la Torre (LAM/Pytheas/AMU) report on behalf of a larger collaboration:

We observed the field of the GRB 240414A (Caputo et al., GCN 36083) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. In a single exposure of 60s in the r-band at 02:56:37UT on 2024-04-14 (36 min after the trigger), we clearly detect a source consistent with the XRT error:
The preliminary magnitude derived for that source is
r = 17.61 +/- 0.01 mag (AB)
The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitude is not corrected for Galactic extinction.
Spectroscopy observations using MISTRAL are currently on going.
We acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean-Pierre Troncin for the MISTRAL observations.