Markarian 501

Markarian 501 ( Mrk 501, and Mkn 501 ) is a blazar in the constellation Hercules, which was systematically observed for the first time by Benjamin Markarian. He is about 500 million light years ( according to other data, 300 million light years) from Earth. In its center is a black hole of about 0.9 to 3.4 billion solar masses. The resulting jet beam has nearly the speed of light is directed towards the Earth.

Markarian 501 is one of Markarian 421 to the next and most high-energy gamma-ray sources. It is observed since 1995 systematically with HEGRA in La Palma. In 1997, several high-energy eruptions were recorded, the intensity ranged up to ten times that of the Crab Nebula.

Markarian 501 is also an important object to validate new theoretical physical approaches. After Floyd plug found no evidence of non- constancy of the speed of light in 2003 from the observational data, was with the 17 meter MAGIC Telescope on La Palma, an outbreak observed in July 2005, in which photons in tera electron volt range according to previous evaluations four minutes earlier arrived as photons of about 500 MeV. This is considered an indication of the verifiability of quantum gravity. With the satellite, launched in 2008 FGST these observations should be further improved.