A white dwarf is the exposed core of an aged star, which is reaching the end of its life. As stars up to about 5 times the mass of our Sun age and evolve, they eventually use up the nuclear fuel which powers them and allows them to shine brightly. During this red giant period, a star loses much of its gaseous material into space, leaving behind just its inner core, which then becomes a white dwarf. White dwarfs are very heavy, very compact and very hot. Return to Top Solar System Objects Objects within our Solar System include the Moon, planets and their moons, and comets.
Most stars appear to move very little against the background sky.
Then, the SPAS platform was able to continuously adjust where it is pointing the three instruments in order to track these moving targets. Galaxies are collections of billions of stars orbiting together as islands in the universe. These types of galaxies are called spiral galaxies. Another type of galaxy, called an elliptical galaxy, appears like a fuzzy ball or egg-shaped collection of stars, with out the familiar disk. Normal galaxies , like our own Milky Way, are fairly plan.