{
  "bibcode": "2023GCN.33434....1P",
  "body": "I. P��rez-Garc��a (IAA-CSIC Granada, Spain), A. Maury (Space Obs, Chile), \nE. Fern��ndez-Garc��a, Y.-D. Hu and A. J. Castro-Tirado (IAA-CSIC and \nUMA), on behalf of a larger collaboration, report:\n\n���Following the detection of the very bright GRB 230307A (Burns et al. \nGCNC 33414) by Fermi/GBM (the Fermi GBM team, GCNC 33405; Dalessi, GCNC \n33407; Dalessi and Roberts, GCNC 33411), GECAM (Xiong et al., GCNC \n33406), Solar Orbiter/STIX (Xiao and Krucker, GCNC 33410), AGILE/MCAL \n(Casentini et al., GCNC. 33412), INTEGRAL/SPI-ACS, Mars-Odyssey/HEND \n(Kozyrev et al. GCNC 33413), AstroSat/CZTI (Navaneeth et al. GCNC \n33415), GRBAlpha (Dafcikova et al. GCNC 33418), VZLUSAT-2 (Ripa et al. \nGCNC 33424), Konus-WIND (Svinkin et al. GCNC 33427) and Swift-BAT \n(Tohuvavohu, GCNC 33431), we observed 60% of the preliminary IPN error \nbox (Kozyrev et al. GCNC 33413) with a 0.5m wide-field telescope in the \nvicinity of the BOOTES-7 astronomical station at San Pedro de Atacama \nSpace Observatory. No optical candidate down to 17.4 mag is found on the \nimages (clear filter, 1.6h co-add) starting at 4:36 on Mar 8 UT (i.e. \n12.9 h postburst) within the entire improved IPN position (Kozyrev et \nal. GCNC 33425).���\n\nThis message can be quoted.",
  "circularId": 33434,
  "createdOn": 1678355492000,
  "email": "ajct@iaa.es",
  "subject": "GRB 230307A: optical upper limit",
  "submitter": "Alberto J. Castro-Tirado at IAA-CSIC  <ajct@iaa.es>",
  "eventId": "GRB 230307A"
}