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Fall 2007  Astr 10  11/29  Lecture 4.4  
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"There are 10^11 stars in the galaxy.  That used 
to be a huge number.  But it's only a hundred 
billion.  It's less than the national deficit!  
We used to call them astronomical numbers.  Now 
we should call them economical numbers."
--Richard Feynman

TODAY: OUR MILKY WAY GALAXY
Spiral arms and spiral arm theories
     Figs. 22.33, 22.35, 22.28, 22.37 (*.gif)
     (Fix, _Astronomy: Journey to the Cosmic Frontier_, 4/e)
     TireTagz.com, HokeySpokes.com
Dark matter
     Figs. 22.29(b), 22.30 (*.gif)
     (Fix, _Astronomy: Journey to the Cosmic Frontier_, 4/e)
[Milky Way nucleus]
[Milky Way evolution]
In-class activity 27 (*.pdf)
CPS activity: Quiz 11 review
     You must use your own clicker for participation credit

NEXT TIME 
Quiz 11 Announcements
     Tuesday, 12/4, 1:00-1:15 PM
     Closed-book, closed-notes
     Five multiple-choice questions
          (one for each Q11.x learning goal)
     No work needs to be shown; no partial credit
     No scantrons; circle answers directly on Quiz
     **USE YOUR OWN UNIQUE 4-DIGIT P.I.N.**