Chapter 28 • Electromagnetic Spectrum • The range of light from short to long wavelengths • The Doppler Effect • Whether stars are moving toward or away from Earth • Redshift • Star is slowly moving away from Earth • Blueshift • Movement of a star toward earth Star Characteristics • Constellations • A group of stars that seem to form a pattern in the night sky Big Dipper Little Dipper • Circumpolar constellations • Revolve around the North Pole so that they can be seen all year long • Magnitude • Apparent magnitude • Absolute Magnitude • The brightness of a star • How bright a star appears to be • How bright a star really is (also called Luminosity) Distance in space • Astronomical Unit • 150 million kilometers, the average distance between the earth and the sun • Light-year • Measure of distance in space • 9.5 trillion kilometers Color of Stars • Cool stars • Red • Warm stars • Bluish-white • Galaxy • A system containing millions to billions of stars • Milky Way • spiral