1. SMALLEST LARGEST UNIVERSE SOLAR SYSTEM STARS GALAXIES MILKY WAY
TIME
SPACE
EVERYTHING
SOLAR SYSTEM
STARS
GALAXIES
PLANETS
MILKY WAY
SUN
NORTH STAR
OTHER CRAP

2. Thought Question:
If you could see stars during the day, this is what the sky would look like at noon on a given day. The Sun is near the stars of the constellation Gemini. Near which constellation would you expect the Sun to be located at sunset?
Leo
Cancer
Gemini
Taurus
Pisces
Answer: FIRST DAY EXAMPLE QUESTION – 3 (10% correct; 90% after discussion)

3. Thought Question
Which of the following describes when constellations are visible from San Diego (if it is dark enough and the clouds cooperate)?
You could observe any constellation tonight at midnight.
You could observe any constellation sometime during the night.
You could observe any constellation on some night during the next year.
Some constellations will never be visible from here.
answer: D (80%)
starter question for first lecture to test that they read?

4. CONSTELLATIONS: for orienting ourselves in the sky:
NORTH STAR
Astronomers have difficult problem – no laboratory … find in sky
How many think they know which is the North Star?
Constellations will have same pattern over your lifetime
BUT whole sky moves around

5. Being a Good Astronomer
ATMOSPHERE
Complications in finding things:
Earth is a sphere (people in different places see different stars)
Earth rotates (stars continually move across sky)
Earth orbits the Sun (stars don’t appear in same place from month to month)
Some of our targets are moving too…

6. Being a Good Astronomer
ATMOSPHERE
HIGH ALTITUDE
LOW ALTITUDE
High in the sky is best because…
the more atmosphere you have to look through:
the more light is blocked
the more the colors are affected
EXPLAIN!! (as class intro); atmosphere is the enemy (though air is delicious to breathe); transparency demonstration?

7. Where in the Sky? To describe position in sky, need two coordinates:
ZENITH
To describe position in sky, need two coordinates:
Altitude (ALT): angle above horizon
0º: horizon
90º: zenith
Direction (DIR): angle clockwise from N measured around horizon
0º: N º: S
90º: E º: W
NORTH STAR E N S W
NORTH STAR
BOARD DRAWING to label altitude, direction; give students time to take notes
fist for a 10º increment
talk about instruments for observing mini-projects E S N W

8. Being a Good Astronomer
ATMOSPHERE
Best telescopes usually scheduled months in advance:
must be able to predict when an object will be up
light from Sun, Moon should not interfere

9. Stars Move?
leave as a mystery for now…

10. Thought Question
In the past, several TV shows (NBC Nightly News, The Daily Show) had opening graphics which showed the Earth spinning the wrong way. If you were watching Earth from a stationary position out in space (as shown below), what direction does it spin?
Left to right
Right to left
answer: A (80%)

11. Celestial Sphere
Stars appear to move as if attached to a sphere rotating around Earth
Celestial poles: above Earth’s N and S poles
Celestial equator: directly above Earth’s equator

12. Earth Surface Coordinates
NORTH POLE
90º N
EQUATOR 0º
blackboard drawing?
SOUTH POLE
90º S

13. Celestial Coordinates
NORTH CELESTIAL POLE
NORTH CELESTIAL POLE
RIGHT ASCENSION LINES
CELESTIAL EQUATOR
Earth lat., long. change slowly due to plate movements; star RA, DEC change very slowly due to motions
DECLINATION LINES
SOUTH CELESTIAL POLE
SOUTH CELESTIAL POLE

14. Celestial Coordinates
north celestial pole
declination (DEC): like latitude on Earth
north celestial pole: +90º
celestial equator: 0º
south celestial pole: -90º
right ascension (RA): like longitude on Earth
BUT… counted in hrs, increases toward east
Earth lat., long. change slowly due to plate movements; star RA, DEC change very slowly due to motions

15. The Sky from San Diego
circumpolar: stars that don’t rise or set for a person
Most stars rise in east half of sky, and set in west half:
LOOKING NORTH
LOOKING SOUTH
NORTH CELESTIAL POLE
- USE THIS ONE!!
Starry night movies don’t show up too well
 stars circle in 23h56m E S N W
HORIZON

16. Thought Question
If you watched the star pictured below from San Diego over several hours, what would happen?
Its altitude and direction wouldn’t change.
Its altitude would change, but direction wouldn’t.
Its direction would change, but altitude wouldn’t.
Both its direction and altitude would change.
answer: D (20%) E N S W
HORIZON

17. Using a Telescope A telescope pointing at one ALT and DIR doesn’t move
BUT a star’s ALT and DIR both change during night
Is there a better way?
example: radar tracking of planes; artillery,spotlights are on alt-az mounts
video links are to Starry Night movies