{
  "version": 2,
  "body": "B. Schneider (CEA Paris-Saclay), C. Adami (LAM), E. Le Floc'h, \nD. Turpin, D. Götz (CEA Paris-Saclay) S. D. Vergani, A. Saccardi \n(GEPI, Observatoire de Paris), S. Basa, A. Le Van Suu (LAM) report \non behalf of a larger collaboration:\n\nWe observed the field of GRB 221009A (Dichiara et al., GCN 32632; \nVeres et al., GCN 32636) using the T120cm telescope at Observatoire \nde Haute-Provence (France). Four exposures were obtained in the \nr band (2x300s + 2x600s), three exposures in the i band (3x600s) \nand the z band (1x300s + 2x900s) from 2022 12 Oct 19:11:05 UT to \n2022 12 Oct 20:41:23 UT (mid time ~78h after trigger). In the \ncombined frame, we clearly detect the source in the three filters \nand obtain the following magnitudes:\n\nr = 20.23 ± 0.09 mag (AB)\ni = 18.91 ± 0.11 mag (AB)\nz = 18.35 ± 0.13 mag (AB)\n\nThe photometric calibration was performed using nearby stars from \nthe PanSTARRS catalog and magnitudes are not corrected for Galactic \nextinction.\n\nThese values are consistent with observations obtained at a similar \ntime by Bikmaev et al. (GCN 32743).\n\nFurther observations using the MISTRAL instrument mounted on the \nT193-OHP are planned for the coming nights.\n\nWe acknowledge the excellent support from Observatoire de Haute Provence, \nin particular François Huppert and Jérome Schmitt.",
  "bibcode": "2022GCN.32753....1S",
  "createdOn": 1665751252000,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>",
  "circularId": 32753,
  "format": "text/plain",
  "eventId": "GRB 221009A",
  "editedOn": 1731773891089,
  "subject": "GRB 221009A: OHP optical observations",
  "email": "benjamin.schneider@cea.fr",
  "submitter": "Benjamin Schneider at CEA  <benjamin.schneider@cea.fr>"
}