... Behemoth black hole found in an unlikely place . ... Fermi mission finds hints of gamma-ray cycle in an active galaxy . ... Astronomers using data from NASA s Fermi Gamma-ray Space Telescope have detected hints of periodic changes in the brightness of a so-called active galaxy, whose emissions are powered by a supersized black hole. ... Astronomers refer to these as active galaxies. More than half of the gamma-ray sources seen by Fermi s LAT are active galaxies called blazars, like PG 1553+113. ...