| A | B |
|---|
| constellations | pattern of stars named after animals, people, or objects |
| absolute magnitude | measure of the light actually given off by a star |
| circumpolar stars | stars visible year-round |
| apparent magnitude | measure of the light received from a star as viewed from Earth |
| parallax | apparent shift in position of an object when viewed from different positions |
| light-year | distance light travels in one year |
| spectrum | different wavelengths of light seperated by a prism |
| spectroscope | instrument used study a star's chemical composition |
| photosphere | layer of the sun from which light is given off |
| chromosphere | intermediate layer of the sun's atmosphere, red color |
| corona | largest layer of the sun's atmosphere |
| solar wind | electrically charged particles that continually escape from the corona |
| sunspots | cooler, darker areas on sun's surface |
| prominences | huge, arching columns of gas |
| solar flares | eruptions of gases near a sunspot, may disrupt radio signals |
| binary system | two stars orbit each other |
| main sequence | 90% of all stars, upper left to lower right on H-R diagram |
| nebula | large cloud of gas and dust in space |
| giant | core contracted, outer layers expand as H used up` |
| white dwarf | core of star runs out of fuel, outer layers escape, core contracts |
| supergiant | massive stars, late stage of large star, heavy elements form, outer layers expand |
| neutron star | final stage of some stars, core collapses, very dense |
| supernova | late stage in large stars, core collapses, outer portion explodes |
| black hole | final stage of very massive stars, core collapses in on itself, nothing escapes its gravity field |
| galaxy | large group of stars, gas, and dust held together by gravity |
| big bang theory | universe began expanding out of a huge explosion 15 billion years ago |
