VERITAS observations of M87

M87 is a giant radio galaxy located at 16Mpc away and is observed from radio to TeV gamma-rays. Its jet features are well studied in radio, optical, and X-ray. The proximity of M87 provides a unique opportunity for multi-wavelength observations to study the source and mechanisms of high energy emission from active galactic nuclei. The VERITAS atmospheric Cherenkov telescope array detected gamma-ray emission above 250GeV from M87 in 2007 and 2008. The 2008 observation was part of a long-term monitoring study coordinated between 3 TeV gamma-ray experiments, H.E.S.S., MAGIC, and VERITAS, resulting in the detection of multiple TeV flares. The monitoring campaign is continued in 2009 and we will present preliminary results from VERITAS observation.