TITLE: GCN CIRCULAR NUMBER: 415 SUBJECT: GRB 990907 optical observations DATE: 99/09/26 09:08:01 GMT FROM: Alberto Castro-Tirado at LAEFF-INTA GRB 990907, optical observations -------------------------------------- Javier Gorosabel, LAEFF-INTA (Madrid) Alberto Castro-Tirado, LAEFF-INTA (Madrid) and IAA-CSIC (Granada) Ian Bond, Nick Rattembury and Phil Yock, University of Auckland Pam Kilmartin, University of Canterbury T. Sumi (Japan) Hernan Muriel, IATE (Cordoba) Enrico Costa, IAS (Frascati), on behalf of the BSAX team report: "We have obtained three 10-minute exposures of the BeppoSAX position of GRB 990907 (Gandolfi et al. GCN 404, 405) with the 0.61-m Mount John University Observatory (MJUO) telescope. The images were taken on Sep 9.40 UT through a broad band filter (R + I bandpass). After a visual comparison with the Digital Sky Survey, no sources varying by more than 0.3 mag were seen to the DSS-2 limit within the BSAX NFI error box (GCN 409) in agreement with the negative results provided by Palazzi et al. (GCN 413)."