To date, only three objects have been firmly established as very high-energy
gamma-ray sources in the Northern sky: the Crab nebula, which is a plerion, and
the two blazars Markarian 501 and Markarian 421. This paper reviews the most
striking results obtained for these sources by the CAT atmospheric Cherenkov
imaging telescope.Comment: 4 pages, 7 figures, to appear in Proc. of the 36th Rencontres de
Moriond on "Very High-Energy Phenomena in the Universe'' (Les Arcs, France
