Star Wheel Challenge

Palomares 4-H Astronomy

Make, or purchase, a planisphere (more commonly known as a star wheel). A planisphere is a device for showing you what stars will be above the horizon at any specific time.

In the following, use STANDARD time

1. Set your star wheel for 10:00 PM on July 22. Which of the following constellations can you observe (if the sky is clear!):
   • ___ Taurus
   • ___ Cygnus
   • ___ Scorpius

2. Which horizon is Scorpius near? __________________ Aquila ________________________

3. Now set your planisphere for 3:00 AM on July 23. Which of the following are now, or still, visible?
   • ___ Taurus
   • ___ Cygnus
   • ___ Scorpius

4. At 10 PM on July 22, is the entire constellation of Pegasus visible? _____
   At 3:00 AM on July 23, is it visible? _____
   At midnight, what horizon is it near? _____________

5. Set the dial for 5:00 AM on July 23. Which of the folowing constellations are visible?
   • ___ Leo
   • ___ Sagittarius
   • ___ Pegasus
   • ___ Taurus
   • ___ Cepheus
   • ___ Ursa Minor
   • ___ Bootes Minor

6. Will Orion be visible on July 23? If so, at what time would you have to look for it?

7. Follow the constellations through one complete rotation of the dial. Note that some constellations never go completely below the horizon. These are called circumpolar constellations (they depend on the latitude of your location). List three cicrumpolar constellations:
   • __________
   • __________
   • __________

8. Set your star wheel for today's date, at 9:00 PM. Name at least 5 constellations you can see:
   • __________
   • __________
   • __________
   • __________
   • __________

9. Find the constellation of Aquila (the Eagle) and its brightest star (biggest dot) Altair. Find the rising, culminating (crossing the north-south line -- that is, the time it reaches the highest part of the sky), and the setting time of this star on June 22:
   • Rising: __________
   • Culminating (highest): __________
   • Setting: __________

10. If any planets are visible tonight, in what constellations would you look for them? (Hint: planets won't appear on your star wheel because they move around. However, planets always stay along a line called the "ecliptic", which is the plane of our solar system. The ecliptic is marked on your star wheel, usually as a dashed line across the sky, running from east to west. If any planets are visible, they are somewhere along that line.)
    • __________
    • __________
    • __________