A large star that has consumed all its hydrogen and is now fusing heavier elements 

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A type of radioactive decay in which the atomic nucleus emits an alpha particle thereby transforming or decaying into a new atomic nucleus

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Electromagnetic radiation coming from every direction in the universe, considered the remnant of the big bang and corresponding to the black-body radiation of 3 K, the temperature to which the universe has cooled

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Explains how the solar system was created from a nebula cloud of gas that formed the star and planets

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Radioactive decay in which an electron is emitted

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The splitting of the nucleus of an atom into two or more nuclei

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How astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now—and it is still stretching

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A large explosion that signals the death of a massive star

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Scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures

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A positively charged particle that consists of two protons and two neutrons bound together. Symbol= 42He

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An extremely large star that has consumed all its hydrogen and is now fusing heavier elements

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Combining lighter atomic nuclei to form a heavier nucleus

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A fast-moving electron emitted by radioactive decay of substances. Symbol=0-1e

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Any star that is fusing hydrogen in its core and has a stable balance of outward pressure from core nuclear fusion and gravitational forces pushing inward.

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What stars like the Sun become after they have exhausted their nuclear fuel

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