Lecture13

Lecture13 - The Sun Radius 6.9 x 108 m(109 times Earth Mass...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 The Sun Radius: 6.9 x 10 8 m (109 times Earth) Mass: 2 x 10 30 kg (300,000 Earths) Luminosity: 3.8 x 10 26 Watts • Over 99.9% of solar system’s mass. • Made mostly of H/He gas (plasma). • Converts 4 million tons of H mass into energy each second. Why does the Sun shine? Is it on FIRE? Is it on FIRE? Luminosity ~ 10,000 years Chemical Energy Content Is it on FIRE? … NO! Luminosity ~ 10,000 years Chemical Energy Content
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Is it CONTRACTING? Luminosity Gravitational Potential Energy Is it CONTRACTING? ~ 25 million years Luminosity Gravitational Potential Energy Is it CONTRACTING? … NO! ~ 25 million years Is it powered by NUCLEAR ENERGY? Luminosity ~ 10 billion years Nuclear Potential Energy (core) Is it powered by NUCLEAR ENERGY? … YES! Luminosity ~ 10 billion years Nuclear Potential Energy (core) E = mc 2 - Einstein, 1905 Gravitational equilibrium: The outward push of pressure balances the inward pull of gravity
Background image of page 2
3 Weight of upper layers compresses lower layers Gravitational
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/26/2008 for the course ASTR 110 taught by Professor Roussev during the Fall '07 term at Hawaii.

Page1 / 8

Lecture13 - The Sun Radius 6.9 x 108 m(109 times Earth Mass...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online