  The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a
low-energy threshold, has detected very-high-energy gamma rays from a giant
flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C
279, at a distance of more than 5 billion light-years (a redshift of 0.536). No
quasar has been observed previously in very-high-energy gamma radiation, and
this is also the most distant object detected emitting gamma rays above 50
gigaelectron volts. Since high-energy gamma rays may be stopped by interacting
with the diffuse background light in the universe, the observations by MAGIC
imply a low amount for such light, consistent with that known from galaxy
counts.
