{
  "bibcode": "2024GCN.36124....1S",
  "circularId": 36124,
  "createdOn": 1713219133178,
  "eventId": "GRB 240415A",
  "subject": "GRB 240415A: OHP/T193 optical observations",
  "submitter": "Benjamin Schneider at MIT <bschn@mit.edu>",
  "submittedHow": "web",
  "body": "B. Schneider (MIT), C. Adami,  O. Ilbert, N. A. Rakotondrainibe (LAM/Pytheas/AMU), D. Turpin, E. Le Floc’h (CEA Paris-Saclay), A. Saccardi, S. Vergani (GEPI/Obs. de Paris) report on behalf of a larger collaboration:\n\nWe observed the field of the GRB 240415A (Fermi GBM team, GCN 36107; Moss et al., GCN 36108; Evans et al., GCN 36109) and its afterglow candidate (Pankov et al., GCN 36118, GCN 36121; Moskvitin et al., GCN 36122; Reguitti et al., GCN 36123) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. A total of 6 exposures (5x600s + 1x480s) were obtained in the r-band at 20:37:17.5 UT on 2024-04-15 (~14.1h after the trigger). In the combined frame, we clearly detect the optical afterglow and measure the following preliminary magnitude:\n\nr = 21.67 +/- 0.10 mag (AB)\n\nThe photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitude is not corrected for Galactic extinction.\n\nWe acknowledge the excellent support from Observatoire de Haute-Provence and in particular Jean Balcaen for the MISTRAL observations."
}