Transcript What you need to know

Astronomy 1020-H
Stellar Astronomy
Spring_2016
Day-6
Course Announcements
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Smartworks Chapter 1: Grades will be downloaded
sometime this weekend.
SW-2 … hop to it.
1st set of Dark Sky observing nights:
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Tues. Feb. 2 & Mon. Feb. 8 – 7:30pm at the observatory.
Tues. Feb. 9 is the weather backup if both are cancelled.
Lab This Week
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Blackbody Curves and UBV Filters
What you need to know:
A Blackbody is a perfect emitter.
Stars are NOT blackbodies.
The Stefan-Boltzmann Law (Chapter 5): F = sT4
Position
Is the horizon shown a real
physical horizon, or an
imaginary plane that extends
from the observer and Earth
out to the stars?
Can the observer shown see an
object located below the
horizon?
Celestial Sphere Rotation
Star B
2
Star A
1
Celestial Sphere
Celestial Sphere
3
1
4
Is there a star that is in an
unobservable position?
When a star travels from being
below the observer’s horizon
to being above the observer’s
horizon, is that star rising or
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3
4
Celestial Sphere
Rotation
Figure 2
Horizon
Tutorial: Position – p.1
 Work with a partner
 Read the instructions and questions carefully
 Talk to each other and discuss your answers with each
another
 Come to a consensus answer you both agree on
 If you get stuck or are not sure of your answer ask
another group
 If you get really stuck or don’t understand what the
Lecture Tutorial is asking as one of us for help
Colored Card Question
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In what direction is
the observer facing?
Celestial Sphere Rotation
Star B
2
Star A
1
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A) toward the South
B) toward the North
C) toward the East
D) toward the West
2
Celestial Sphere
Celestial Sphere
3
1
4
3
4
Celestial Sphere
Rotation
Figure 2
Horizon
Colored Card Question

Imagine that from your current location you
observe a star rising directly in the east. When
this star reaches its highest position above the
horizon, where will it be?
A. high in the northern sky
B. high in the southern sky
C. high in the western sky
D. directly overhead
Colored Card Question
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Where would the
observer look to see
the star indicated by
the arrow?
Star B
2
Star A
1
2
Celestial Sphere
Celestial Sphere
3
1
4
A. High in the Northeast
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B. High in the Southeast
C. High in the Northwest
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D. High in the Southwest
Celestial Sphere
Rotation
Horizon
I Realize this is Like Trying to Drink
from a Fire Hose