GCN 43858: GRB 260226A: LCOGT Optical Upper Limit

2026-02-27T03:17:12.219Z | rev 0 | event: GRB 260226A
R. Strausbaugh (Eastern Illinois University), A. Cucchiara (NASA) report on behalf of a larger collaboration:

We observed the Fermi GRB 260226A field (Fermi GBM Team, GCN 43840)  with the LCOGT 1-meter Sinistro instrument at the McDonald Observatory, USA site, on February 27, from 01:46 to 02:18 UT (corresponding to 15.15 to 15.68 hours after the GRB trigger time) with the SDSS r and i filters.

We performed a series of 3x300s exposures in i-band and r-band.  We do not detect any uncatalogued sources within the Fermi LAT error region (Depalo et al., GCN 43850) in either band.

The following 5-sigma upper limits are calculated using the PanSTARRS catalog as reference:

r > 21.6
i > 21.1

These magnitudes are not corrected for galactic extinction.