AS102 -The Astronomical Universe

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AS102 -The Astronomical Universe
Instructor Professor Tereasa Brainerd TAs Ren
Cashman Katie Garcia
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AS102 - Major Topics

• Where are we (earth, sun) in the universe?
• What are stars?
• How are stars born, how do they live out their
  lives and how do they die?
• What is the Milky Way?
• What are galaxies, and what can they tell us
  about the universe as a whole?
• Has the universe always existed? If not, how did
  it begin?

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The boring details
Class web page is http//firedrake.bu.edu/AS102/AS
102.html Textbook Stars, Galaxies Cosmology
(5th edition) by Bennett, Donahue, Schneider and
Voit Grade Breakdown Labs (best 5 of 6 day
labs 2 night labs) 25 Homework (approx.
10, 2 lowest scores dropped) 15 Midterm
Exams (15 each, best 2 of 3) 30 Final
Exam 30 In-class minute papers 5
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Day Labs - Rooms B4 606

• Text of day labs will be posted on the course web
  page.
• You are responsible for printing out hard
  copies of the labs and bringing them to your lab
  section!
• Luminosity Brightness (B4)
• Parallax (B4)
• Gravity (B4)
• Spectroscopy (B4)
• Stellar Spectra (Computer Lab, 606)
• Hubble Law (Computer Lab, 606)
• Next week 2/19-2/21 will be orientation and math
  review in lab sections.

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Night Labs - Roof of CAS Building
Every CLEAR Monday, Tuesday, and Thursday night
starting at 830pm Call 617-353-2630 after 600pm
for status of night labs. Night Lab 1 - must
attend one session between 01/19 and 03/4 Night
Lab 2 - must attend one session between 03/15
and 04/27
Night lab reports are due by 500pm on the day
after the last scheduled opportunity to do the
lab (03/05, 04/28)
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The eastern view from the roof. Notice the red
brick wall on the bottom and the concrete wall to
the right.
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Wear lots of warm clothes (including a hat and
gloves)! You will be outside on the roof for
about an hour. Bring a small flashlight! It will
be dark, and you will need to write things down
during the lab.
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Get your night labs done as early as you can!

• Night lab 1 is only offered before Spring Break
• Night lab 2 is only offered after Spring Break
• If you wait until the very last night to go up to
  the roof, and it happens to be cloudy (or
  snowing) that night, youre out of luck and will
  get a zero on the night lab

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Homework Assignments
candy
stapler

• will be due about every other week
• will be posted on course web page
• hand in using the Homework Box in the main
  Astronomy Office (Room 512/514)
• your two lowest scores (including zeros due to
  illness) will automatically be dropped
• late homework is not accepted

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In-class Minute Papers

• Last 5 minutes of class (1215pm to 1220pm)
  write a few sentences on one of the following
  something you found particularly interesting in
  the days lecture, something you found
  particularly confusing in the days lecture,
  questions you have about topics that were covered
  in the days lecture
• Use a full-sized sheet of paper (8.5x11)
• Be sure to print your name clearly
• You can miss up to 3 minute papers (due to
  illness or family emergency) without it affecting
  your grade

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Physics Mathematics

• Astronomers use laws of physics to interpret
  observations of the universe
• Physics is a mathematical description of nature
• Focus will be on qualitative understanding, but
  will be times when we need to use mathematics
• Math will be at level of high school algebra
• Will practice ratios, units conversion, powers of
  10 next week in lab
• Get a copy of Prof. Marschers math primer from
  the course web page

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How to succeed in this course

• Come to class every day, do the labs, do the
  homework, and hand everything in on time
• Read along in the book (see the lecture outline
  in the syllabus)
• Start studying early for exams
• Ask lots and lots of questions!!!!

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Exam Dates

• Midterm 1 - Thursday, February 11
• Midterm 2 - Tuesday, March 23
• Midterm 3 - Tuesday, April 20
• Final Exam - Tuesday, May 5 (900am - 1100am)

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Astronomy as a Science

• What is the scientific method?
• What makes a good theory?
• Does the scientific method have an endpoint? Why
  or why not?
• In what way is astronomy a passive science
  compared to other sciences (e.g., chemistry,
  biology)?

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Learning about the Universe(where do the data
come from?)
Its all about LIGHT! Light comes in different
colors Light interacts with matter
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The Solar System
Earth is one of 8 planets that orbit the sun.
Planets closest to the sun are hard and rocky.
Planets farthest from the sun are huge gas balls.
Is there anything special about the Earths
location?
Sun is a perfectly ordinary, garden-variety star.
Mass of 2x1030 kg, about 5 billion years old.
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Stars in the Night Sky
Look closely at this picture on the course
website. The projector does not do it
justice!! What differences might you see? Do all
stars seem the same?
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Baby Stars
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Star Guts
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The Milky Way
Time exposure image taken at the Cerro Telolo
observatory in Chile. Whats the little bright
blob on the horizon?
Our home galaxy is called the Milky Way Galaxy.
It is a vast collection of stars, gas (mostly
hydrogen) and dust.
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M31 (the Andromeda Galaxy)our sister galaxy
Like the Milky Way, M31 is a spiral galaxy where
most of the stars reside in a thin disk. The sun
resides in the outer reaches of the Milky Ways
disk. Any idea where all the stars you see around
M31 are actually located?
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M51 (the Whirlpool)
Bright blue stars are extremely young Bright pink
blobs are hot hydrogen gas Notice how they all
fall along the spiral arms!
Take a look at this on the course web page. This
is one of the most beautiful galaxies in the
universe!!!
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Not all galaxies are spirals
The Large and Small Magellanic clouds (irregular
galaxies)
M87 - a giant elliptical galaxy
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The universe is full of galaxies!
An image of an essentially random region of the
sky. There are over 2000 galaxies in the image,
and in the entire universe there are at least 100
billion galaxies in the observable universe.
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Minute Paper

• A few sentences on one of the following
• something you found particularly interesting
  today
• something you found particularly confusing
  today
• questions on things from today that you would
  like to know more about
• Be sure to PRINT your name legibly