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This image shows quasar PG 0052+251, which is 1.4 thousand million light-years from Earth, at the core of a normal spiral galaxy. Captured by the Hubble Space Telescope.


Also called QSO, Quasi-Stellar Object. One of a number of distant celestial objects larger than stars but smaller than galaxies. Quasars give off blue light and powerful radio waves. Even though quasars seem to be much smaller than galaxies, they give off thousands of times more energy. Some scientists think that quasars are associated with black holes.