TITLE: GCN CIRCULAR NUMBER: 6060 SUBJECT: GRB061217: MAGIC telescope GeV observation DATE: 07/01/30 18:19:08 GMT FROM: Markus Garczarczyk at MPI/MAGIC Scapin V. and Garczarczyk M., Bastieri D., Fagiolini M., Galante N., Gaug M., Longo F., Mizobuchi S., Piccioli A. and Stamerra A. report for the MAGIC collaboration: The MAGIC Imaging Atmospheric Cherenkov Telescope performed a follow-up observation of the SWIFT-BAT burst GRB061217 (GCN circular 5926, Barthelmy S.D. et al.). We received the GCN alert at T0+13s, however, because of observation constraints, data taking with MAGIC started at T0+773s, when the GRB zenith angle reached 60 degree. The observation continued for 66min. No evidence for VHE gamma-ray emission above the analysis threshold of 325 GeV was found. A preliminary analysis, for the hypothesis of steady emission and assumption of a differential photon spectral index of -2.5, yields the following 95% CL differential flux upper limits (inc. 30% systematic error on the absolute flux level): E(300-500 GeV) : 0.53 x 10^(-10) erg/cm^2/s E(500-1000 GeV) : 0.35 x 10^(-10) erg/cm^2/s The upper limits apply of the time window between T0+773s and T0+2573s (the first 30min of the MAGIC data sample). This message can be cited.