TITLE:   GCN CIRCULAR
NUMBER:  37712
SUBJECT: GRB 241002B: PRIME near-infrared detection in 2nd epoch
DATE:    24/10/04 15:08:22 GMT
FROM:    Joe Durbak at UMD <gcn.joedurbak@gmail.com>

J. Durbak (UMD), O. Guiffreda (UMD), S. Atri (U Rome), A. S. Kutyrev (NASA/GSFC), E. Troja (U Rome), K. De (MIT), S. B. Cenko (NASA/GSFC)

Following up on the previous PRIME detection (GCN 37700), the transient field was observed a second time ~40 hours after the initial Fermi GBM detection (GCN 37668).

At the position of the optical counterpart reported by GOTO (GCN 37676), and the previously detected PRIME source (GCN 37700) we detect a fading uncatalogued source in J and H bands. Using nearby VISTA Hemispherical Survey (VHS) and 2MASS stars for preliminary calibration we derive the following magnitudes, not corrected for Galactic extinction:  

Filter | Mag(AB)      |
-------|--------------|
J      | 20.6 +/- 0.2 |         
H      | 20.3 +/- 0.1 |          

Further follow-up observations are encouraged.

PRIME 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).

We thank the Osaka University observers at PRIME and the staff at SAAO for their support with these observations.