TITLE: GCN CIRCULAR NUMBER: 43858 SUBJECT: GRB 260226A: LCOGT Optical Upper Limit DATE: 26/02/27 03:17:12 GMT FROM: Robert Strausbaugh at Eastern Illinois University 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.