Download Astronomy

Name_____________________________________________
Period___________
The Sky test REVIEW KEY
1. When is the constellation Ursa Major visible from Pittsburgh? Year Round
2. Where does the celestial equator cross the horizon? East and West
3. If you live on the equator, where would the celestial equator be in your sky? It would run from East to
West and directly overhead through your zenith
4. What is the difference between 1st magnitude and 2nd magnitude stars? 1st magnitude are brighter
5. Describe some of the different kinds of star charts available: Seasonal star charts good for a specific
date and time, planispheres good all year, equatorial star charts good all year for +60 to -60
declination
6. You just got off a plane in an unknown location somewhere in the Northern Hemisphere. Once you
locate Polaris in your sky, how can you use that to figure out your latitude?
Your latitude will be the same as how high Polaris is above the northern horizon. We are at 40 degrees
latitude and Polaris is 40 degrees above our northern horizon.
7. Where did most of the constellation names originate? What about star names? Many constellation
names come from Greek culture. Star names come from Arabic
8. What is the meridian on the celestial sphere? The line running from North to South and through your
zenith
9. What is declination? Measure of the distance north or south of the equator
10. What is Right Ascension? Measure of the east-west distance in the sky
11. What is your zenith? The point right above the observer’s head
Name_____________________________________________
Period___________
12. How do you know the declination of your zenith? Same as your latitude
13. What is the horizon? Visual boundary between land and sky
14. How high above your horizon is your zenith? 90 degrees
15. How high above your horizon would you see the North Celestial Pole and Polaris? The same as your
latitude (40 for us)
16. If Star A has a magnitude of -1.0 and Star B has a magnitude of 1.0, which star is brighter? Star A
17. What is the declination of the Celestial North Pole? 90 degrees
18. What does apparent visual magnitude (mv) measure? What is the highest magnitude of stars that are still
visible with the naked eye?
How bright stars look from Earth. The dimmest we can see are about a magnitude of 6
19. Would Polaris be visible for an observer at -70o in the Southern Hemisphere? No, they are too far south
20. How do stars near the Celestial Equator appear to move? From east to west
21. How do stars near the Celestial North Pole appear to move? In a circle around Polaris
22. If the north celestial pole appears on your horizon, what is your latitude? 0 degrees at the equator
23. How are modern-day constellations defined? 88 Regions of space with well-defined borders
Name_____________________________________________
Period___________
24. Where should you look to see the planets that wander among the stars? Why?
Look to the ecliptic, because that is the plane on which all planets orbit the sun.
25. What is the tilt of the earth’s axis of rotation relative its plane of revolution?
23.5 degrees
26. What are circumpolar constellations? Stars so near the north celestial pole that they don’t rise or set
27. What is an asterism? A recognizable pattern in the sky
28. What is the ecliptic? The plane of earth’s orbit, the apparent path the sun travels in our sky over the
course of a year
29. What is the Celestial Sphere? An imaginary sphere surrounding Earth on which all of the celestial
objects are “painted”. The sphere appears to spin around us every 24 hours.
**On a drawing of the celestial sphere similar to the one on the right,
Celestial north pole
be able to identify:
Zenith
Celestial
equator
 the Celestial North Pole

the Celestial Equator

the zenith

the horizon
horizon
**On an equatorial constellation chart (the big rectangular one):
 be able to identify declination, right ascension, the ecliptic, and the celestial equator
 be able to locate a star/constellation using RA and Dec coordinates
 be able to predict which constellation will be visible at a given location in your sky at a given time
 be able to compare brightness of various stars