# Astronomy 100 Are All Stars the Same?. Answer Now: Why does the Sun shine? Are all stars the same as our Sun? (How or how not?) Goal: – Be able to tell.

## Presentation on theme: "Astronomy 100 Are All Stars the Same?. Answer Now: Why does the Sun shine? Are all stars the same as our Sun? (How or how not?) Goal: – Be able to tell."— Presentation transcript:

Astronomy 100 Are All Stars the Same?

Answer Now: Why does the Sun shine? Are all stars the same as our Sun? (How or how not?) Goal: – Be able to tell me how stars are born – Know what stars are made of – Know how stars shine – (if we have time) Know how stars die Vocabulary: Planck curve, luminosity, H-R Diagram, absolute magnitude, apparent magnitude, fusion, H, He, CNO Cycle, protostar, nebula, protostar, hydrostatic equilibrium, interstellar medium, compression wave,

http://www4.nau.edu/meteorite/Meteorite/Images/PlanckCurve.jpg Planck Curve - Temperature DIRECTLY related to peak wavelength.

Luminosity – Apparent magnitude – Absolute magnitude – Luminosity is the total brightness Temperature or Type – Can tell temp from color – Can tell type from spectrum, temp or color Types: O, B, A, F, G, K, M

http://www.eso.org/gallery/d/4380-2/phot-28c-07.jpg

http://raviramanathan.blogspot.com/2007/05/life-cycle-of- star.html

It all starts with gas Interstellar medium Gas cloud (nebula) Compression wave Pockets of compacted gas Gravity further squeezes gas PROTOSTAR! Squished enough (enough energy) fusion begins STAR!

E=mc 2 H+H+H+H+H+H = He + H + H+ energy

Hydrostatic Equilibrium Energy from fusion

http://people.maths.ox.ac.uk/schmitz/Files/starlife.jpg

And in the end… < 4 Solar Mass – when finished fusing H, begins to fuse He Ffffffft (planetary nebula) White dwarf/black dwarf > 4 Solar Mass – when finished fusing H, begins to fuse He – when finished fusing He, begins to fuse C, N, O (shells) Kerblewie! (supernova) Black hole/neutron star

Review – define 3 of the terms at the beginning of this lecture. Quiz Review

High Mass Stars My candle burns at both ends; It will not last the night; But ah, my foes, and oh, my friends-- It gives a lovely light. Emily Dickinson