What observation in astronomy, made AFTER the discovery of quasars, was a big help to astronomers in figuring out what quasars really were? O the discovery that the Milky Way Galaxy has a black hole at the center with enough mass for 4 million Suns the understanding that most stars become white dwarfs when they die and white dwarfs are much smaller than main-sequence stars O the discovery of exoplanets (planets orbiting other stars) throughout the Galaxy O the discovery that the galaxies mostly show a red shift the discovery of Herbig-Haro objects around newly forming stars

What observation in astronomy, made AFTER the discovery of quasars, was a big help to astronomers in figuring out what quasars really were? O the discovery that the Milky Way Galaxy has a black hole at the center with enough mass for 4 million Suns the understanding that most stars become white dwarfs when they die and white dwarfs are much smaller than main-sequence stars O the discovery of exoplanets (planets orbiting other stars) throughout the Galaxy O the discovery that the galaxies mostly show a red shift the discovery of Herbig-Haro objects around newly forming stars