TITLE: GCN CIRCULAR NUMBER: 2790 SUBJECT: GRB041006: Liverpool Telescope optical observations DATE: 04/10/08 22:10:58 GMT FROM: Alessandro Monfardini at JMU/Liverpool Robotic Tele A. Monfardini (Liverpool), C. Mottram (Liverpool J.M. Uni.), C. Guidorzi (Liverpool), N. Tanvir (U. of Hertfordshire), C. Mundell (Liverpool), I. Steele (Liverpool), R. Priddey (Hertfordshire), M. Hughes (Hertfordshire), R. Smith (Liverpool), A. Gomboc (Liverpool), S. Fraser (Liverpool), M. Bode (Liverpool), A. Newsam (Liverpool) report: We observed the optical afterglow of GRB 041006 with the 2.0m Liverpool Telescope on La Palma. We obtained BVRI imaging commencing 8.2 hours after the burst. We report preliminary R-band estimates: R = 20.4 +/- 0.1 mag at Oct 6.92 UT (exposure time = 600s) R = 20.6 +/- 0.1 mag at Oct 6.98 UT (exposure time = 600s) These values were derived applying zero points inferred from the Landolt standard stars as cited in Fugazza et al (GCN 2782), which result in measured magnitudes ~0.3 mag fainter than those given in the USNO catalogue. star RA Dec R mag err ---------------------------------------------------------- U0900_00213234 00:54:47.045 +01:14:05.60 17.75 +- 0.04 U0900_00213423 00:54:50.131 +01:12:10.33 18.90 +- 0.04 In summary, we confirm the R-band magnitude measured by Fugazza et al (GCN 2782) at 7.07UT.