Download Day-6

Astronomy 1010
Planetary Astronomy
Fall_2015
Day-6
Time to Re-Calibrate
Course Announcements
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Smartworks Chapter 1: Due TODAY!
Grades will be downloaded on Saturday.
No class Monday (Labor Day)
Read Chapter 2.2, 2.3, 2.4
How is the lunar observing going?
How is the sunset/sunrise observing going?
Next week:
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Dark Night Observing on Tues. 9/8 & Thur. 9/10
Sat. 9-5: Football vs Mercer, 4pm; Tailgate at 1pm
Useful Information for Next Lab
 Rotating Sky
 ClassAction Web Site (Link from
apsu.edu/astronomy)
 Print the instructions BEFORE you come to
class!
Definitions & Terms -1
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Circumpolar Star: A star which stays above the horizon at all
times at the observers location.
Zenith: The point directly overhead, 90° from all horizons
(assuming they are flat). It does NOT have an azimuth
associated with it.
Nadir: The point directly under your feet, opposite the zenith
Altitude: A measure of the height of an object from the
ground up. It is measured perpendicular to the horizon. The
horizon is 0° altitude. The Zenith is 90° altitude.
Azimuth: The point along the horizon –measured eastward
from the north point- where you measure the altitude. Runs
for 0° in the North, to 90° due East, 180° South; 270° West.
Use the Big Dipper in the northern sky
as a way to find other groups of stars
Use Summer Triangle to find
constellations during evenings
Use Winter Triangle to find
constellations during evenings
Stuff in Chapter 2
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Coordinates
Position
Daily Motion (spin of Earth on its axis)
Visibility of the sky
Year Motion (Earth orbits the Sun)
Seasons (tilt of the Earth’s axis)
Precession of the equinoxes
Motion and phases of the Moon
Eclipses
Coordinates
Stuff in Chapter 2
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Coordinates
Position
Daily Motion (spin of Earth on its axis)
Visibility of the sky
Year Motion (Earth orbits the Sun)
Seasons (tilt of the Earth’s axis)
Precession of the equinoxes
Motion and phases of the Moon
Eclipses
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
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Star A
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Celestial Sphere
Celestial Sphere
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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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Celestial Sphere
Rotation
Figure 2
Horizon
Tutorial: Position – p.1
 Work with a partner
 Read the instructions and questions carefully
 Discuss your answers with each other
 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