{
  "editedBy": "Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of N. Passaleva at Sapienza University of Rome <niccolo.passaleva@uniroma1.it>",
  "subject": "GRB 251221A: PRIME near-infrared observation",
  "format": "text/plain",
  "bibcode": "2025GCN.43183....1P",
  "submittedHow": "web",
  "submitter": "N. Passaleva at Sapienza University of Rome <niccolo.passaleva@uniroma1.it>",
  "circularId": 43183,
  "createdOn": 1766419362082,
  "editedOn": 1766438987470,
  "body": "N. Passaleva  (U Rome),  O. Guiffreda (UMD), M. El Kabir (U Rome), J. Durbak (UMD), E. Troja (U Rome), A. S. Kutyrev (NASA/GSFC), S. B. Cenko (NASA/GSFC) \n\nFollowing the Fermi/Swift (Fermi GBM team, GCN 43164; Ambrosi et al., GCN 43166) detection, we observed the transient field in J and H filter with PRIME. Observations started ~15.5 hours after the initial trigger. \n\nUsing Two Micron All Sky Survey (2MASS) nearby stars for preliminary calibration we detect an uncatalogued source at the position reported by Rakotondrainibe et al. (GCN 43168) and Volnova et al. (GCN 43180). We derived the following magnitudes not corrected for galactic extinction:  \n\nJ = 20.27 ± 0.09 \n\nPRIME is a 1.8m telescope with 1.56 square degree FOV (0.5 arcsec/pixel) located in Sutherland, South Africa at the South African Astronomical Observatory (SAAO) (Kutyrev et al. 2023, Yama et al. 2023, Durbak et al. 2024). \n\nWe thank the Osaka University observers at PRIME and the staff at SAAO for their support with these observations. ",
  "version": 2,
  "eventId": "GRB 251221A"
}