Fermi LAT

NASA's Fermi Gamma-ray Space Telescope sees NGC 1275 (center), the core member of the Perseus cluster of galaxies, as a source of high-energy gamma rays, but the earlier Compton mission did not. The beam from this galaxy's central black hole strengthened in the years between the two missions. Brighter colors indicate higher numbers of gamma rays at energies above 200 million electron volts.