Stars

1. a nuclear reaction in which lightweight nuclei combine into heavier nuclei
3. energy output from the surface of a star per second, measured in watts
5. relatively cool, dark spots appearing on the surface of the photosphere
7. a sudden eruption of particles and radiation from the surface of the Sun
8. small, extremely dense remnant of a star whose gravity is so immense that not even light can escape its gravity field
9. a stream of high-speed, ionized particles flowing outward through the solar system from the Sun's corona
10. top layers of the Sun’s atmosphere

1. a nuclear reaction in which an atomic nucleus splits into smaller, lighter nuclei releasing energy
2. group of stars that forms a pattern in the sky
4. two stars gravitationally bound together and orbiting about a common center of mass
6. a cloud of interstellar dust or gas or both, which collapses on itself as a result of its own gravity
7. massive explosion that occurs when the outer layers of a star are blown off