Astronomy DSST Practice Test Questions and Answers

Quasar Short for "quasi-stellar radio source," a bright, point-like object that produces the luminosity of 100 to 1,000 galaxies within a region the size of a solar system. Pulsar A rapidly rotating neutron star which emits radiation in magnetic pulses. Redshift A shift in the lines of an object's spectrum toward the red end. It indicates that an object is moving away from the observer. The larger it is, the faster the object is moving. Asterism A cluster of stars (or a small constellation). Equinox Either of the two celestial points at which the celestial equator intersects the ecliptic plane. Ecliptic Plane the plane of the Earth's orbit around the Sun. Brown Dwarf "Failed" star; a star not massive enough to sustain nuclear fusion. Calderas Depressions that form when a volcano collapses, as opposed to craters formed by meteoroid impact. Red Giant A star that expands and cools once it runs out of hydrogen fuel. White Dwarf Stage in which a star has used up its helium and its outer layers escape into space, leaving behind a hot, dense core that contracts. Galactic Bulge Also called nuclear bulge, this is a swelling at the center of spiral galaxies. Bulges consist of old stars and extend out a few thousand light-years from the galactic centers. Neutron Star The small, dense remains of a high-mass star after a supernova. Radio Galaxy Very bright, often giant, elliptical galaxy type that emits as much or more energy in the form of radio wavelengths as it does wavelengths of visible light. Seyfert Galaxy Type of active galaxy whose emissions come from a very small region within the nucleus of an otherwise normal-looking spiral system.