Chapter 3 – Stars and Galaxies Vocabulary Name ________________________ Class ______ Lesson 1 1. 2. 3. 4. 5. 6. apparent appearing to the eye or mind apparent magnitude measure of how bright an object appears from Earth astronomical unit average distance between Earth and the Sun light-year distance that light travels in 1 year luminosity true brightness of an object parallax apparent change in an object’s position caused by looking at it from two different points 7. spectroscope instrument that spreads light into different wavelengths Lesson 2 1. chromosphere orange-red layer of a star’s atmosphere, between the photosphere and the corona 2. convection zone region above the radiative zone of a star where hot gas moves up toward the surface and cooler gas moves deeper into the interior 3. corona wide, outermost layer of a star’s atmosphere 4. globular round, sphere-shaped 5. Hertzsprung-Russell diagram graph that plots luminosity v. temperature of stars 6. nuclear fusion process that occurs when the nuclei of several atoms combine into one larger nucleus 7. photosphere apparent surface of a star’s atmosphere 8. radiative zone shell of cooler hydrogen above a star’s core 9. star large ball of gas held together by gravity with a core so hot that nuclear fusion occurs 10. stellar anything related to stars Lesson 3 1. 2. 3. 4. 5. 6. black hole object whose gravity is so great that no light can escape nebula cloud of gas and dust, where stars form neutron neutral particle in the nucleus of an atom neutron star dense core of neutrons that remains after a supernova supernova enormous explosion that destroys a star white dwarf hot, dense, slowly cooling sphere of carbon Lesson 4 1. Big Bang theory states that the universe began from one point billions of years ago and has been expanding ever since 2. dark matter matter that emits no light 3. Doppler shift shift to a different wavelength as waves travel toward or away from the point of observation 4. galaxy huge collection of stars Chapter 3 – Stars and Galaxies Vocabulary Name ________________________ Class ______ Lesson 1 Apparent apparent magnitude astronomical unit light-year Luminosity parallax spectroscope Chromosphere convection zone corona globular Hertzsprung-Russell nuclear fusion photosphere radiative zone Star stellar Lesson 2 Lesson 3 black hole nebula neutron neutron star supernova white dwarf Chapter 3 – Stars and Galaxies Vocabulary Name ________________________ Class ______ Lesson 4 Big Bang theory dark matter Doppler shift galaxy