TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4413 SUBJECT: GRB051227: further analysis of VLT images DATE: 05/12/29 18:30:10 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, S. Covino (INAF/OABr), D. Malesani (SISSA), S. Piranomonte, L.A. Antonelli (INAF/OAR), S. Campana (INAF/OABr), report on behalf of the MISTICI collaboration: We further analyzed our VLT images (Malesani et al., GCN 4404, 4412) of GRB 051227 (Barbier et al., GCN 4397; Hullinger et al., GCN 4400; Barthelmy et al., GCN 4401). Optimal subtraction performed with the ISIS package on our two set of images (taken on Dec 28.2 and 29.2 UT) clearly shows a dimming of the source S1 (Malesani et al., GCN 4404). A figure showing the result of the subtraction can be found at the following URL: http://www.sissa.it/~malesani/GRB/051227/subtraction.jpg This message can be cited.