chapter14

chapter14 - Our Star The Sun Why was the Suns energy source...

Info iconThis preview shows pages 1–24. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

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

Unformatted text preview: Our Star The Sun Why was the Suns energy source a major mystery? Is the Sun on FIRE? If it is on fire, it must be burning a chemical fuel. How long can this burning last given it has a finite mass with a maximum chemical energy content? Is the Sun on FIRE? Luminosity ~ 10,000 years Chemical Energy Content Is it on FIRE? NO! It would burn to an ash is 10,000 years! Luminosity ~ 10,000 years Chemical Energy Content from Mass Is the CONTRACTING due to its own gravity? Luminosity Gravitational Potential Energy ~ 25 million years Luminosity Gravitational Potential Energy Is it CONTRACTING? NO! ~ It would only last 25 million yrs Why does the Sun shine? It can be powered by NUCLEAR ENERGY! Luminosity ~ 10 billion years Nuclear Potential Energy (core) E = mc 2- Einstein, 1905 The Sun has layers that get more dense as they go in toward the center What started the nuclear reaction? GRAVITY Things get hotter as they get compressed!!! Weight of upper layers compresses lower layers Gravitational equilibrium: Energy provided by fusion maintains the pressure Gravitational contraction: Provided energy that heated core as Sun was forming Contraction stopped when fusion began What is the Suns structure? 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 Solar wind: A flow of charged particles from the surface of the Sun Corona: Outermost layer of solar atmosphere ~1 million K Chromosphere: Middle layer of solar atmosphere ~ 10 4 - 10 5 K Photosphere: Visible surface of Sun ~ 6,000 K Convection Zone: Energy transported upward by rising hot gas Radiation Zone: Energy transported upward by photons Core: Energy generated by nuclear fusion ~ 15 million K Why cant chemical burning be a...
View Full Document

This document was uploaded on 10/26/2011 for the course UW 20 at GWU.

Page1 / 63

chapter14 - Our Star The Sun Why was the Suns energy source...

This preview shows document pages 1 - 24. Sign up to view the full document.

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