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Science Ch. 19
| Question | Answer |
|---|---|
| The color of a start depends on its | temperature |
| What color are the hottest stars? | blue |
| The H-R diagram shows the relationship of a star's surface temperature | absolute magnitude |
| What objects are formed from the materials in the core of a supernova? | black holes and neutron stars |
| What is the term for the actual brightness of a star? | absolute magnitude |
| What is the term for the brightness of a star as it appears to an observer on Earth? | apparent magnitude |
| What is the term for a gigantic explosion that causes the death of a large star | supernova |
| What is a the term fora massive and dense object from which even light cannot escape its gravity? | black hole |
| What type of star is bright and hot? | blue star |
| What type of star is bright and cool? | red giant |
| What type of star is dim and hot? | white dwarf |
| What type of star is dim and cool? | red dwarf |
| Name the three major types of galaxies? | Spiral galaxy, irregular galaxy, and elliptical galaxy |
| Why do scientists study distant galaxies? | To learn what early galaxies looked like |
| Is the universe expanding outward or inward? | Outward |
| What is the term for radiation left over from the big bang that fills all of space? | cosmic background radiation |
| What is the term for the type of galaxy that has a center bulge and outer "arms"? | spiral galaxy |
| What is the term for the type of galaxy with a bright center and little to no dust and gas? | elliptical galaxy |
| What is the term for the theory that states the universe began with a huge explosion? | Big Bang Theory |
| What is the term for a large cloud of dust and gas where new stars are formed or stars explode? | nebula |
| What is the term for the study of the origin, structure, and future of the universe? | cosmology |
| Scientists think that the universe will do what? | Expand forever |
| What does a star's color indicate? | It's temperature |
| The H-R diagram shes the relationship between a star's surface temperature and what? | It's absolute magnitude |
| What star is the hottest? | Main-sequence blue star |
| According to the big bang theory, how old is the universe? | 13.7 billion years old |
| What type of galaxy do the scientists think the milky way is? | spiral galaxy |
| Which is a bigger: a nebula or a galaxy? | Galaxy |
| What part of the modern H-R diagram do cool, bright red stars appear? | bottom right |
| What is one way scientists use to calculate the age of the universe? | They measure the distance from Earth to various galaxies |
| Why do black lines appear on an absorption spectrum? | Black lines appear where colors of light are absorbed by a star's atmosphere |
| What do the pattern of lines in a star's absorption spectrum represent? | Some of the elements in the star's atmosphere |
| Elliptical galaxies and the halos of spiral galaxies contain groups of stars called what? | globular clusters |
| According to the big bang theory, what filled the universe after the original explosion? | cosmic background radiation |
| The universe is organized according to what? | a loosely arranged structure |
| What are the three major types of galaxies identified by Edwin Hubble? | spiral, elliptical, and irregular |
| Why do scientists study distant galaxies to learn about early galaxies? | Because it takes a long time for light to travel through space, looking at distant galaxies shows what early galaxies looked like |
| What type of star has used up all of its hydrogen and is the leftover center of an old star? | white dwarf |
| Which is larger: a galaxy or a globular cluster | galaxy |
| What do the patter of lines in a star's absorption spectrum represent? | Some of the elements in the star's atmosphere |
| Elliptical galaxies and the halos of spiral galaxies contain groups of stars called | Globular clusters |