1. The Rest of the Universe Stars and Galaxies

2. Stars constellations- an imaginary picture made by groups of stars; example: The Big Dipper The color of the star indicates the temperature. Blue is the hottest, red is the coolest. apparent magnitude- how bright a star looks from Earth. Things far away appear to look dim.

3. A Stars Life 1. Birth- created from cloud of gas and dust 2. Adulthood- uses hydrogen and helium for nuclear fusion fuel 3. Old age- enlarges into a red giant or supergiant 4. Uses up its fuel and becomes a dwarf star (white, then brown then black when doesnt give off any more light) 4. Explodes in a supernova! 5. Neutron star (2-3 times mass of our sun) 5. Black hole (>7 times mass of our sun) or 4.

4. Galaxies galaxy- a group of stars, gas and dust held by gravity Three types: spiral (our Milky Way), elliptical and irregular It takes the Sun 240 million years to revolve around the center of the Milky Way Stars revolve around the center of their galaxy. Most galaxies have a black hole in the center! Light-year= the distance light travels in one year, about 9.5 trillion km.

5. Whats Next The universe is expanding, constantly getting bigger, so things are getting further apart. It could a) keep expanding forever b) slow down and stay the same size c) slow and start shrinking No one knows what will happen!