TITLE: GCN GRB OBSERVATION REPORT NUMBER: 175 SUBJECT: GRB 981220 optical R and I observations DATE: 98/12/28 17:11:54 GMT FROM: Adriano Guarnieri at O.A.di Bologna GRB 981220 optical observations C. Bartolini, S. Bernabei, I. Bruni, A. Guarnieri, A. Piccioni, University of Bologna, and N. Masetti and G. Pizzichini, ITEsre-CNR, Bologna, communicate: "Four 40 min. R-band and one 40 min. I-band CCD frames of the error box of GRB 981220 (Hurley et al., GCN #160) were obtained with the 1.5-m telescope of the University of Bologna from 1998 December 22.86 UT to 23.02 UT. A preliminary analysis of the R band frames shows no variable object within 0.3 mag. In the I band frame no new evident objects with respect of the Palomar Digitized Sky Survey were observed inside the mentioned error box. The seeing was 3.8"; the measurable limiting magnitude was R ~ 22 (for the sum of the four CCD frames) and I ~ 19.7. This message may be cited.