Why are stars different sizes?
(MUSIC) Narrator: Welcome to Space Place Musings, where an expert answers questions from our Space Place museum partners across the nation. Im Diane Fisher of the New Millennium Program, and our expert is Dr. Marc Rayman, an astrophysicist at the Jet Propulsion Laboratory. Marc, our loyal friends at the Discovery Museum Science and Space Center, in Sacramento, California, have a star question Ive often wondered about myself. Why are stars different sizes? Rayman: Great question! Even apart from how bright they appear, which is affected by how far they are from us, stars come in a tremendous range of sizes. Narrator: Right. But heres what I dont understand. The laws of physics must dictate that a star must have at least a certain mass for its nuclear fires to ignite. So why aren’t stars all the same mass? Rayman: It does indeed take a certain mass to sustain the nuclear reactions that make stars shine. That’s why there is a minimum mass for stars; it is about 8% of the mass of the Sun,
