ASTR 115: Stars and galaxies
"We are explorers. Our curiosity propels
us to push the frontiers of human
possibility and imagination. This is the
core of NASA's mission - We dare to
explore."
- Michael D. Griffin
Former NASA Administrator
April, 2008
“Somewhere, something incredible
is waiting to be known.”
- Carl Sagan
Astronomer
ASTR 115 – Stars and galaxies
Instructor:
Tracy Furutani (tfurutan@northseattle.edu)
Textbook (required): Astrophysics is Easy! by Michael Inglis
Course website: http://facweb.northseattle.edu/tfurutan
then click on the Astronomy 115 link
Note: This a hard-link integrated studies course with Barbara
Goldner’s MATH 098 class. The classes run concurrently.
Course Expectations
• Basic math skills (basic algebra, scientific notation,
unit conversion)
• Basic writing (referencing, researching, word
processing)
• Computer literacy (using Web resources)
Assignments
Labs: Hands-on exercises to reinforce lecture topics. Also,
time will be set aside to teach problem solving techniques
and review relevant lecture material. May be done in
groups or individually.
Poster Project: Visual presentation of the term project.
Handout will follow. Includes the writing of an abstract
(summary) prior to the presentation.
Homework: Roughly one assignment per week, to be done
outside of class time, though you should ask questions
related to the homework in class. May require some
outside reading. Each person should turn in their own
assignment.
Course Objectives
• Explore the following topics: inventory of space, astronomical
distances, forces that govern matter, basics of light and matter
(spectroscopy), astronomical instrumentation, structure and
energy source of the sun and other stars, stellar birth, life and
death, galactic structure and classification, large scale
structure of the universe, fate of the universe.
• Learn basic problem solving techniques.
• Learn basic observing and experimental techniques.
Some things we will discuss:
Some things we will discuss:
Some things we will discuss:
Some things we will discuss:
Why do we have seasons on earth?
1. Change of earth’s
distance from the
sun
2. Tilt of earth’s
rotation axis relative
to its orbit
3. Greenhouse effect
4. Mysterious alien
technology
Why do we have seasons on earth?
1. Change of earth’s
distance from the
sun
2. Tilt of earth’s
rotation axis relative
to its orbit
3. Greenhouse effect
4. Mysterious alien
technology
Seasons
Will a human set foot on Mars in your
lifetime?
1. Yes
2. No
Perspective
The Earth was small, light blue, and so
touchingly alone, our home that must
be defended like a holy relic. The Earth
was absolutely round. I believe I never
knew what the word round meant until I
saw Earth from space.
- Aleksei Leonov, USSR
Perspective
It suddenly struck me that that tiny
pea, pretty and blue, was the
Earth. I put up my thumb and shut
one eye, and my thumb blotted out
the planet Earth. I didn't feel like a
giant. I felt very, very small.
— Neil Armstrong (Apollo XI)
The view of the Earth from the
Moon fascinated me—a small disk,
240,000 miles away. . . . Raging
nationalistic interests, famines,
wars, pestilence don't show from
that distance.
— Frank Borman (Apollo VIII)
Perspective and Scale in Our Solar
System
Our Local Inventory:
What makes up our star system?
2)
A single central star of spectral class “G2”, luminosity
class V (yellow-dwarf, main sequence).
Two sub-stellar giant planets (Jupiter & Saturn)
3)
Two icy-gas hybrid planets (Uranus & Neptune)
1)
All of the above planets have large systems of satellites; some are
planet-sized: Io, Europa, Ganymede, Callisto, Titan, and Triton)
4)
Four much smaller rocky planets. (Mercury, Venus, Earth, & Mars)
5)
Two areas of failed planetary debris
a) one rock-based (asteroid belt between Mars and Jupiter)
b) one ice-based (Kuiper Belt starting at Neptune’s orbit) .
6)
Several “dwarf planets” (e.g., Pluto)
7)
An extended distribution of ejected or non-condensed debris
(Oort Cloud)
Asteroid belt (rocks) between Mars
and Jupiter
Icy Kuiper Belt Objects (KBOs) lie
beyond Neptune’s orbit
Oort Cloud is well beyond Pluto, or
Sedna, or Eris, or any other KBO
Solar System (Is this scale right?)
1. Yes
2. No
Solar System (Is this scale right?)
1. Yes
2. NO
Sun
Venus
Earth
Mars
Mercury
Sun
Jupiter
Saturn
Neptune
Uranus
Pluto
Missoula
The Sun and the Solar System
Any study of the solar system must start with the Sun…..
1) The sun contains 99.9% of all the mass in the solar system (Jupiter has
most of the remaining 0.1%)
2) The sun dominates energy (and light) production at all frequencies
(except in radio waves where human activity is stronger!)
3) Solar energy largely determines the temperatures of every object in the
solar system.
4) Material from the solar atmosphere is the dominant component of
interplanetary space.
Compared to the Sun, the planets are nearly inconsequential…..
Neptune
Uranus
Saturn
The Sun
dominates the
solar system.
Jupiter
Earth
Sol
The places we are most
interested in don’t add up to
very much……
Earth
Ganymede
Io
Moon
Venus
Titan
Mars
Mercury
Europa
Triton
Callisto
Pluto
Our Local Inventory:
Where to learn more?
www.nineplanets.org
www.earthsky.org