GCN Circular 39670
Subject
GRB 250309B: PRIME near-infrared detection
Date
2025-03-11T19:46:22Z (2 days ago)
From
O. Guiffreda at UMD <oriogui@umd.edu>
Via
Web form
GRB 250309B: PRIME near-infrared detection
O. Guiffreda (UMD), J. Durbak (UMD), E. Troja (U Rome), A. S. Kutyrev (NASA/GSFC), S. B. Cenko (NASA/GSFC)
Following the Fermi GBM trigger (GCN 39635), we observed the transient field in J and H filters with PRIME ~1.5 days after the Fermi detection.
At the position of the optical counterpart AT2025dws (Stein et al., GCN 39639), we detect an uncatalogued source in both J-band and H-band. Using nearby VISTA Hemispherical Survey (VHS) stars for preliminary calibration we estimate J~20 AB mag.
Further observations are planned.
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.