Hot dust-obscured galaxies. Image of a portion of the all-sky survey from NASA's Wide-field Infrared Survey Explorer (WISE), highlighting the first of about 1,000 hot dust-obscured galaxies (hot DOGs) found by the mission (magenta circle). Hot DOGs are among the most powerful galaxies known and are turning out to be among the most luminous, or intrinsically bright objects known, in some cases putting out over 1,000 times more energy than our Milky Way galaxy. Yellow circles are active supermassive black holes found by WISE, which are much more common.