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Marano- Astron. Star
Marano -Astronomy- Stars
| Question | Answer |
|---|---|
| stars | ball of dust and gas (H and He) |
| star's color | depends on temperature |
| blue-colored star | 30,000 degrees |
| white-colored star | 7500 degrees |
| yellow-colored star | 5 to 6,000 degrees |
| red-colored star | 3500 degrees (coolest) |
| Stars are classified by | temperature, brightness |
| Before telescopes, the brightest star in the sky was called | first magnitude |
| Before telescopes, the dimmest star in the sky was called | sixth magnitude |
| Apparent magnitude | how bright a star looks |
| Absolute magnitude | actual temperature |
| HR diagram | shows relationship between a star's temperature and absolute magnitude |
| blue stars expand into | giants or supergiants |
| main sequence | where stars spend most of their lives |
| white dwarfs | small, hot stars that are the leftover centers of old stars, near the end of life |
| nebula | large cloud of gas and dust in space |
| gravity causes a nebula to | condense (squish), get hot and create the core |
| nuclear fusion | when hydrogen joins with hydrogen, helium and hydrogen + a lot of energy |
| When nuclear fusion begins | a star is born |
| Young stars have a lot of | hydrogen |
| Older stars have less hydrogen and more | helium |
| When most of hydrogen fuel is gone, the outer layer of gas begins to expand, cool and glow red- called | Red (super) giant |
| When a red giant uses up most of its hydrogen and helium, gravity squishes the star, and it gets hotter-called | White dwarf |
| No energy, heat or light just a small, dense, cold lump called | Balck Dwarf or Cold Star |
| supernova | a massive star that may explode in a flash of light |
| Death of a large star by explosion happens when | outer layers collapse too quickly |
| neutron star | some exploded particles pull together |
| pulsar | spinning neutron star |
| black hole | after a supernova particles clumped together to size of small point- even light |