Science ch 3 sec 4-5 Flashcards
what are binary stars
a star system that contains two stars
what are star systems
a group of two or more stars
what is an eclipsing binary
a star system in which one star periodically blocks the light from another
how do we know planets go around other stars
the planet 51 pegasi moved back and forth slowly around an invisible mass
what are the three types of galaxies
spiral, elliptical, and irregular galaxies
what are spiral galaxies
a galaxy whose arms curved outward in a pinwheel pattern
what are elliptical galaxies
a galaxy shaped like a flattened ball, containing only old stars
what are irregular galaxies
a galaxy does not havea regular shape
how are galaxies moving
the big bang explosion is still moving them
what was the big bang
a giant explosion that created the universe
how did the solar system form
a long time ago, dust got together. it first formed a spnning disk. more got together and it got very hot and formed the sun. the rest of the dust formed the other planets.
what will happen to the universe
1) the universe will continue to expand and eventually all the stars will burn out
2) it all will come togerther forming the big crunch
