TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3211 SUBJECT: GRB 050408: Mercator Optical Observations DATE: 05/04/09 23:43:33 GMT FROM: Klaas Wiersema at GRACE/U of Amsterdam P. Curran, K. Wiersema (University of Amsterdam), K. Lefever, H. van Winckel, C. Waelkens (Katholieke Universiteit Leuven), O. van Braam, Y. Grange, R. de Rooij, A. de Vries, L. Waters, (University of Amsterdam), G.Bourban, G.Burki, F.Carrier (Geneva Observatory), E. Rol (University of Leicester) report: "On 09 April we continued our observations (GCN 3200) of the optical afterglow reported by de Ugarte Postigo et al. (GCN 3193) of the HETE-2 GRB 050408 (Sakamoto et al., GCN 3189) at the 1.2m Mercator Telescope at La Palma. The R-band observation started at 05:15 UT and consisted of 2 x 8 minute exposures, with midpoint 13.02h after burst. We calibrated our photometry using the USNO-B catalogue. We find a marginal R-band detection of 22.3 +/- 0.3. We thank the staff of the Mercator Telescope for the excellent assistance."