Optical observations of TeV Blazars: preliminary results

I.ANDRUCHOW; SERGIO A. CELLONE; GUSTAVO E. ROMERO

Malargüe, Mendoza, ARGENTINA

Congreso; 50 Reunion de la Asociacion argentina de Astronomia; 2007

Asociacion Argentina de Astronomia

Recently, Cherenkov gamma-ray telescopes (H.E.S.S., MAGIC) have detected some blazars, in particular BL Lac objects, at very high energies -- E > 1 TeV --. These are well-known and relatively nearby  blazars, because TeV radiation is efficiently absorbed by the extragalactic infrared background radiation. However, the available information about their general characteristics is still scarce. Specifically, we study here the variability behaviour, at optical wavelengths, of a sample of TeV-blazars. The observations were made using the 2.15-m ``Jorge Sahade´´ telescope, at CASLEO, San Juan, Argentina. We are looking for any common features that would allow us to better understand the emission of such very high-energy radiation in these objects.