TITLE: GCN CIRCULAR NUMBER: 35633 SUBJECT: GRB240122A: PRIME near infrared detection DATE: 24/01/25 20:05:40 GMT FROM: Joe Durbak at UMD <gcn.joedurbak@gmail.com> O. Guiffreda (UMD), J. Durbak (UMD), A. S. Kutyrev (NASA/GSFC), E. Troja (U Rome), K. De (MIT), S. B. Cenko (NASA/GSFC) Following the MAXI/GSC detection (Negoro et al. GCN 35593), GOTO optical candidate GOTO24eu/AT2024apy (Kumar et al. GCN 35596), and the Swift afterglow detection (Ambrosi et al. GCN 35600), we observed the transient field using J and H filters with PRIME ~1.5 days after MAXI/GSC detection. At the position of the optical counterpart detected by GOTO, we detect an uncatalogued source in both J and H bands. Using nearby 2MASS stars for preliminary calibration we derive the following magnitudes, not corrected for Galactic extinction: Filter | Mag(AB) | SNR | Seeing | Total exposure time (s) -------|----------------|-----|--------|------------------------- J | 21.02 +/- 0.20 | 6.3 | 1.373” | 1802 H | 20.90 +/- 0.21 | 6.1 | 1.480” | 1544 PRIME is a 1.8m telescope with 1.56 square degree FOV (0.5 arcsec/pixel) located in Sutherland, South Africa. Further observations are planned. We thank the Osaka University observers at PRIME and the staff at SAAO for their support with these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/35633. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...