{
  "bibcode": "2022GCN.32654....1D",
  "body": "J. M. Durbak (UMD), A. S. Kutyrev (NASA/GSFC), I. Andreoni (JSI), K. De\n(MIT), E. Troja (U Tor Vergata/ASU), S. B. Cenko (NASA/GSFC), R. Hamada\n(Osaka U), Y. Hirao (Osaka U), R. Kirikawa (Osaka U), I. Kondo (Osaka U),\nS. Miyazaki (ISAS/JAXA), G. Mosby (NASA/GSFC), T. Sumi (Osaka U), D. Suzuki\n(Osaka U), H. Yama (Osaka U)\n\nWe observed the field of the transient Swift J1913.1+1946 or GRB 221009A\n(Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al.,\nGCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et\nal., GCN Circ. 32650) with the PRIME near-infrared camera mounted on the\n1.8m Telescope at SAAO.\n\nObservations were carried out on 2022-10-09 around 18:50 UT, i.e. about 4.7\nhours from the Swift/BAT detection (Dichiara et al., GCN 32632), 5.5 hours\nafter the Fermi/GBM detection (Veres et al., GCN 32636), and 1 day after\nthe PRIME instrument first light.\n\nWe detected a near-infrared source spatially consistent with the bright\noptical transient previously reported, with preliminary photometry H~12.2\nmag, calibrated against nearby 2MASS sources. Our result is consistent with\nthe REM detection (Brivio et al. GCN 32652) and suggests no significant\nfading between 5.5 hr and 10.5 hr after the GBM trigger.\n\nArchival deep near-infrared images of the field taken with WFCAM during the\nUKIRT Galactic plane survey (Lawrence et al., 2007) do not show any\npersistent source in J and H bands at the transient location.\n\n\nThese results are based on data obtained from PRIME at the South African\nAstronomical Observatory (SAAO), Sutherland, South Africa.",
  "circularId": 32654,
  "createdOn": 1665404159000,
  "email": "igor.andreoni@gmail.com",
  "subject": "GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection",
  "submitter": "Igor Andreoni at JSI  <igor.andreoni@gmail.com>",
  "eventId": "GRB 221009A"
}