TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2635 SUBJECT: GRB 040730: Optical observations DATE: 04/07/31 00:54:27 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC), S. Eguchi (Univ. of Nagoya), A.J. Castro-Tirado (IAA-CSIC), A. de Ugarte Postigo (IAA-CSIC), P. Kilmartin (Univ. of Canterbury), P. Yock (Univ. of Auckland), M. Jelínek (IAA-CSIC) and J.M. Castro Cerón (STScI) report: "We have acquired two set of images of the GRB 040730 error box, provided by INTEGRAL (Gotz et al. GCN 2634), with the 0.6 m telescope (+MOA camera) at the Mt. John Observatory. The observations were performed with the MOA broad R band filter (similar to Ic); individual exposure times were 300 s. The two sets are composed of three images each (Texp = 3 x 300 s), the first one taken on July 30.2992-30.3126 UT (t-to ~ 5.2 hr) and the second one 30.5215-30.5349 UT (t-to ~ 10.7 hr). Visual comparison of the two epochs did not reveal variable sources brighter than Ic ~ 20. We note the severe Galactic extinction in the GRB line of sight (A_I ~ 2.3 mag)." This message may be cited.