Astronomy 305/Frontiers in Astronomy
Professor Lynn Cominsky
Department of Physics and Astronomy
Office: Darwin 329A and NASA E/PO
(707) 664-2655
Best way to reach me:
lynnc@charmian.sonoma.edu
9/2/03
Prof. Lynn Cominsky
1
Astronomy 305/Frontiers in Astronomy
 Book:
On the Cosmic Horizon by
Jeffrey Bennett (Ten Great Mysteries
for Third Millenium Astronomy)
 Course Organization:
 10 Mysteries + three more that I have
added
 And an introduction, and a review
 Interactive lectures – lots of activities!
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Prof. Lynn Cominsky
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Astronomy 305/Frontiers in Astronomy
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Grades
15% - attendance as evidenced by
classroom worksheets (1% per week)
 20% - long, research style paper. Topic due
11/11/03, paper due 12/9/03
 15% for in-class small group presentation
 15% x 2 for “book reports” on your choice
of books from class list, due 9/30/03 and
10/28/03
 20% for short answer final exam, 12/16/03
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Astronomy 305/ Book List
 Black Holes and Time Warps by Kip Thorne
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Black Holes and the Universe by Igor Novikov
Accelerating Universe by Mario Livio
Runaway Universe by Donald Goldsmith
Einstein’s Unfinished Symphony by Marcia
Bartusiak
The Hole in the Universe by K. C. Cole
The Extravagant Universe by Robert
Kirshner
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Astronomy 305/Book List (continued)
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Flash! The Hunt for the Biggest Explosions
in the Universe by Govert Schilling
How the Universe Got Its Spots by Janna
Levin
Wrinkles in Time by George Smoot
Unveiling the Edge of Time by John Gribbin
Before the Beginning by Martin Rees
The Inflationary Universe by Alan Guth
Strange Matters by Tom Siegfried
Cosmic Bullets by Roger Clay and Bruce
Dawson
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Astronomy 305/Book Report grading
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Present a succinct, yet thorough overview of the
book that encompasses the key elements of the
book’s content. The goal here is to convince me that
you have read the entire book.
Connect the book’s main topic to the material
presented during one or more of the classroom
sessions (or chapters of the Jeff Bennett book). Your
goal here is to convince me that you have learned
something about at least one of the subjects we are
discussing in class.
Book report must be well written, and free of
grammatical and spelling errors.
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Astronomy 305/Book Report grading
Book report must not contain any
plagiarized material – use quotes and
refer to page numbers!!
 Book reports are expected to be
approximately 5 pages. Your grade will be
lowered if your report is either too short or
too long. Use 12 point type, double spaced,
and standard margins from Word or other
program.
 Make sure to put your name on the report.
No fancy covers please.
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Other information of interest:
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Class web page:
http://glast.sonoma.edu/~lynnc/courses/a305/
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Prof. J. Tenn’s A305 course information
http://www.phys-astro.sonoma.edu/people/faculty/tenn/A350/
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Prof. G. Spear’s A305 course information
http://www.phys-astro.sonoma.edu/people/faculty/spear/courses/A305.html
My group’s home page: http://epo.sonoma.edu
 Imagine the Universe! http://imagine.gsfc.nasa.gov
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Astronomy 305/Course Outline
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Date
1
9/2/03
Intro/EM Spectrum
2
9/9/03
Black Holes
3
9/16/03
Cosmic Rays
4
9/23/02
Stars and Planets
5
9/30/03
10
Life in Solar System
6
10/7/03
6
Earth-like Planets
7
10/14/03
1
Are We Alone?
9/2/03
Book Topic
Prof. Lynn Cominsky
Due
BR#1
9
Astronomy 305/Course Outline
8
10/21/03
5
Gamma-ray Bursts
9
10/28/03
7
Galaxy Evolution
10 11/4/03
9
Solar Neutrinos
11 11/11/03
8
Universe Shape
12 11/18/03
4
Inflation
13 11/25/03
3
Universe Fate
14 12/2/03
2
Universe Contents
15 12/9/03
9/2/03
Review
Prof. Lynn Cominsky
BR#2
Topic
Paper
10
Early View of the Universe
What do
you
know
about
the
Universe
?
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Introductory Activities
Project group selection
 Assessment Quiz
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Do this as individuals
Cosmic Survey
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Do this in small groups
You are given pictures of different astronomical
objects
Put them in order of size
Put them in order of distance
Put them in order of age
Prof. Lynn Cominsky
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Powers of Ten
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Scientific Notation
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10n means 10 x 10 x 10 x 10 … [n times]
10-n means 1/(10 x 10 x 10 ….) [n times]
10n > 1  it is a 1 followed by n zeroes (102
= 100)
 10-n < 1  it is decimal point, (n-1) zeroes,
then 1 (10-2 = 0.01)
 There are 1010 – 1011 stars in our galaxy, and
a similar number of galaxies in the Universe
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Sizes and Magnitudes
There are 1010 – 1011 stars in our galaxy,
and a similar number of galaxies in the
Universe
 Each star weighs ~1030 kg and contains
more than 1057 atoms
 The radius of a typical star is ~108 m
 Each atom weighs ~10-27 kg and has a
radius of about 10-10 m
 1 light year is 9.5 x 1015 m
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Powers of Ten Video
Produced by Charles and Ray Eames
 Describes the journey into Outer Space
and then into Inner Space
 Each step is a factor of ten in distance
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Let There Be Light!
E=hc/
n=c/
c = 3 x 108 m/s
E = energy
= wavelength
n = frequency
h = Planck’s constant
= 4 x 10-15 eV sec
It’s not just a good
idea, it’s the law!
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Seeing the Light
VLA
COBE IRAS EUVE Chandra GLAST
HST/Keck
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What emits EM radiation?
• Everything does!
• Often called thermal or
blackbody radiation
• the hotter the object, the
shorter the wavelength of
the peak
• the hotter the object, the
more intense the radiation
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What’s a good blackbody?
• Stars
• The Universe!
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Radio
• Cool objects (0 to a few 10s Kelvin)
• Synchrotron radiation: electrons spiralling
around magnetic fields
• Bremsstrahlung: collisionally
accelerated electrons
• Cold molecular clouds
• Planets
• pulsars
• Radio galaxies
• Intergalactic matter
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Microwave
• a bit warmer objects (10s to 100K)
• microwave generator
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warm molecular clouds
Planets
water masers
Galaxies
The Universe!
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Infrared
• warm objects (100s to about 2000 K)
• Nebulae
• Planets
• “Normal” stars
• Enshrouded protostars
• Galaxies
Video from SIRTF
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Visible
• hot objects (2000 to about 10000 Kelvin)
• “Hot” speaker for next week!
• Nebulae
• Planets
• “Normal” stars, sun-like
and hotter
• Galaxies
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Ultraviolet
• hotter objects (10,000 to
about 100,000 Kelvin)
• Nebulae
• Planets with magnetic fields
(aurorae)
• O-F stars
• Pulsars
• Galaxies
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X-rays
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very hot objects (100,000 to a few 106 Kelvin)
Synchrotron radiation
Inverse Compton scattering
Bremsstrahlung
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Planets
O star winds
solar corona
White dwarfs
Pulsars
Black holes
Galaxy clusters
Dark matter, indirectly
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Gamma Rays
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Extremely energetic objects
Radioactive decay (Co56, Ti44)
Fusion
Cosmic ray/gas interaction
matter/antimatter annihilation
magnetic fields
• supernovae
• Diffuse Galactic emission
• Active galaxies
•(some) Pulsars
• black holes
• Gamma Ray Bursts
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Gamma Rays
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Extremely energetic objects
Radioactive decay (Co56, Ti44)
Fusion
Cosmic ray/gas interaction
matter/antimatter annihilation
magnetic fields
• supernovae
• Diffuse Galactic emission
• Active galaxies
•(some) Pulsars
• black holes
• Gamma Ray Bursts
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Other uses for Gamma Rays
New Hulk movie uses LBNL’s
Gamma-sphere
But it really detects gamma-rays,
rather than emitting them.
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Different Views from the Inside
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Invisible Universe GEMS Activity
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Different stations have different types of light
sources and detectors
All stations have same set of materials
Try each of the 5 stations
For each material: Predict whether or not it will
block the light, then test your prediction
Write your predictions and results down on the
worksheets that are provided
Hand in worksheets before leaving class
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