Universe Vocabulary

2. the entire range of wavelengths of all known electromagnetic radiations
5. the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy.
7. a place in space where gravity pulls so much that even light can not get out
9. a narrow band in the Hertzsprung-Russell diagram in which 90 percent of all observed stars are plotted.
11. any particle of matter in the universe attracts any other with a force varying directly as the product of the masses and inversely as the square of the distance between them
12. how astronomers explain the way the universe began
13. the brightness of an object as it appears to an observer on Earth
16. a point at which a function takes an infinite value
17. a very dense object in space that consists of closely packed neutrons and is produced by the collapse of a much larger star
20. the change in wave frequency during the relative motion between a wave source and its observer

1. the magnitude that a star would appear to have if it were located at a standard distance of 10 parsecs.
3. a giant cloud of dust and gas in space
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
6. the cooled remnant of the first light that could ever travel freely throughout the Universe
8. A group of stars seen as forming a figure or design in the sky
10. a system of millions or billions of stars
14. The branch of science that deals with celestial objects, space, and the physical universe as a whole.
15. an optical instrument designed to make distant objects appear nearer.
18. the mean distance from the center of the earth to the center of the sun.
19. the wavelength of the light is stretched, so the light is seen as 'shifted' towards the red part of the spectrum