General information
FTW/3KK reports optical and near-IR observations of the counterpart associated with GRB 250131A, detecting the source in r, i, and J at ~1.65 days after the trigger.
Wavelength coverage
- Gamma-ray: GRB context referenced as triggered by Fermi/GBM (no prompt properties reported in this circular).
- Optical: Detected in r and i.
- Near-IR: Detected in J.
No observations were mentioned for X-ray, UV, millimeter/sub-mm, or radio.
Lightcurve and spectrum
- At 2026-02-01T22:14:35 UT (~1.65 days post-trigger): r = 19.18 ± 0.03 AB mag (PS1-calibrated; not corrected for Galactic extinction).
Redshift
What’s special vs typical