TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3298 SUBJECT: GRB 050421: BOOTES-2 simultaneous optical observations DATE: 05/04/21 07:57:42 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia M. Jelinek, A. J. Castro-Tirado, J. Gorosabel, A. de Ugarte Postigo (IAA-CSIC Granada), P. Kubanek, R. Hudec (Astronomical Institute of the Academy of Sciences, Ondrejov), T. J. Mateo Sanguino (Universidad de Huelva), T. Soria, R. Fernández (EELM-CSIC, Málaga) and J. Fabregat (Universidad de Valencia) report: "The BOOTES-2 very wide field camera, located at the Estación Experimental de La Mayora (EELM-CSIC) in Málaga, observed the region of the sky containing the SWIFT/BAT error box for GRB 050421 (Barbier et al. GCN 3296) as part of its routine observing schedule. A 30 s exposure started at 04:12:00 UT (8 s after the onset of the 10 s long burst), with the previous frame starting at 04:11:00 UT. A limiting (unfiltered) magnitude of 9.0 is derived for any prompt optical flash arising from this event." This message can be quoted.