Vocabulary Science

3. the group of stars that on a graph of spectrum versus luminosity forms a band comprising 90 percent of stellar types and that includes stars representative of the stages a normal star passes through during most of its lifetime.
4. the stellar core left behind after a dying star has exhausted its nuclear fuel and expelled its outer layers to form a planetary nebula.
5. Newton's law that says that every particle attracts every other particle in the universe with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
6. the science that deals with the material universe beyond the earth's atmosphere.
8. a theory that deduces a cataclysmic birth of the universe (big bang ) from the observed expansion of the universe, cosmic background radiation, abundance of the elements, and the laws of physics.
9. a shift toward longer wavelengths of the spectral lines emitted by a celestial object that is caused by the object moving away from the earth.
10. a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space.
11. an enormous cloud of dust and gas occupying the space between stars and acting as a nursery for new stars.

1. an optical instrument for making distant objects appear larger and therefore nearer.
2. a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
7. A group of stars seen as forming a figure or design in the sky,
12. an area of such immense gravity that nothing—not even light—can escape from it.