TITLE: GCN CIRCULAR NUMBER: 8076 SUBJECT: GRB 080805: Faulkes Telescope South optical observations DATE: 08/08/06 20:03:48 GMT FROM: Cristiano Guidorzi at INAF-OAB C. Guidorzi (INAF-OAB), I. Steele and R.J. Smith (LJMU) on behalf of a larger collaboration report: On 2008 August 05 (10:12:35 UT) we began observing the field of GRB 080805 (Pagani et al. GCN Circ. 8059) with the Faulkes Telescope South using the R and i' filters. In our coadded i' frame we marginally detect the optical afterglow (Kruehler et al. GCN Circ. 8060; de Ugarte Postigo et al. GCN Circ. 8061): Telescope Filter T_mid[hr] Exposure[s] Mag ----------------------------------------------------------- FTS i' 5.410 6x300 22.5 +/- 0.4 ----------------------------------------------------------- The calibration was performed using the I magnitudes of several USNOB-1 catalogue field objects. From the comparison with the value reported by GROND (Kruehler et al. GCN Circ. 8060) we estimate an average power-law decay index of ~0.7, consistent with that inferred in the R band (de Ugarte Postigo et al. GCN Circ. 8061).