Part One: Make your Star Wheel.
If you don’t have a planisphere, or “Star Wheel,” you can go to Uncle Al’s Hands-On Universe and Star Wheel site, print the pieces and make one yourself.
- Use the Star Wheel. (25 points)
- Note the marks for the cardinal points on the horizon and daytime hours. (These marks have to be added.)
- Align the date on the disk with the time on the holder.
- Turn your Star Wheel so that the horizon you are facing is at the bottom.
- Locate the constellation you want to find on the disk and then look up at the sky.
- Neatness and accuracy counts.
Part Two: Stars and Constellations: Writing a Conclusion (28 points)
Use a reliable source to identify which mark on your Star Wheel represents the featured stars below. Consider the ten statements, then circle T if the statement is true, circle F if any part of the statement is false. Consider “around” to mean within 30 minutes one-way or the other of exact. Then complete Table 1.
- Put Antares in the constellation Scorpius on the eastern horizon.
T F 1. Antares rises in the southeast and sets in the southwest.
T F 2. Antares rises at around 7 p.m. on June 1.
T F 3. Antares sets around 5 a.m. on June 2.
- Put Altair in the constellation Aquila on the eastern horizon.
T F 4. Altair rises in the southeast and sets in the southwest.
T F 5. On June 1, Altair rises around 8:30 pm.
T F 6. On June 2, Altair sets around 10:30 am.
- Put Albireo in the constellation Cygnus on the eastern horizon.
T F 7. Albireo rises in the north-northeast and set in the south.
T F 8. Albireo spends more time in our sky than Altair.
- Polaris in the constellation Ursa Minor is near the center of your window.
T F 9. Polaris stays in about the same location in our sky as the sky full of stars appears to rotate around it.
T F 10. The constellation Ursa Minor takes around 12 hours to complete one circle around Polaris.
Table 1: Stars in our Sky
|Star||Rising Horizon||Rising time||Setting Time||Time in the Sky|
|Antares||SE (southeast)||7:00 p.m||5:00 a.m.|
- Examine the rising and setting times and positions of the four stars in Table 1. Compare their rising and setting locations with the total amount of time each will be in our sky. Look for a relationship between the rising and setting locations with the amount of time spent in our sky. Write a paragraph with the following parts:
One sentence clearly and succinctly describing the observed pattern, One sentence giving evidence from Table 1 supporting your first sentence, Once sentence giving another convincing example of evidence, One sentence noting a weakness in this research, One sentence that asks a follow-up question.
Part Three: The ecliptic and the zodiac: Analyzing Data (27 points)
The equatorial co-ordinate system describes the position of an object relative to the celestial equator, the great circle on the celestial sphere that lies directly above the Earth’s equator. An object on the celestial equator would have a declination of 0o 00’
Right Ascension, sometimes called the hour angle, is the equivalent of longitude on Earth but measured in hours and minutes. The point in the sky where the path of the ascending Sun crosses the celestial equator is 0hr 00 min.
Table 2 describes the position of the Sun using the equatorial co-ordinate system. Use the side of the wheel with the concentric circles printed. We will use the grid for marking, not the dates along the outer edge of the wheel.
With a pencil, lightly draw a large dot (~3 mm diameter) on the wheel where the Sun is located in the sky each date. Still with pencil, lightly draw in a best-fit curve that will connect the dots in order. This path of connected dots is the ecliptic, the apparent path of the Sun against the background stars. Lightly shade in about 8o both sides of the ecliptic. This is the zodiac, the strip of sky against which the Sun, the Moon, and major planets appear to move.
- Write in the name of the constellation for each date.
|TABLE 2: Position of the Sun among the Constellations|
|Date (2017-8)||Number of days from previous||Right Ascension
|Mar 20||0 hr 00 min||+ 0o|
|Apr 19||30||1 hr 50 min||+ 11o|
|May 20||31||3 hr 50 min||+ 20o|
|Jun 19||30||5 hr 53 min||+ 23o|
|Jul 20||31||8 hr 00 min||+ 21o|
|Aug 19||30||9 hr 56 min||+ 13o|
|Sep 19||31||11 hr 48 min||+ 1o|
|Oct 19||30||13 hr 37min||– 10o|
|Nov 19||31||15 hr 41min||– 20o|
|Dec 19||30||17 hr 51min||– 23o|
|Jan 19||31||20 hr 07 min||– 20o|
|Feb 18||30||22 hr 05 min||– 11o|
|Mar 20||31||0 hr 00 min||+0o|
- What is your astrological “sign”? If you aren’t sure check a horoscope internet site and look for your “sun sign.” ___________________________________
- What is the month and date of your birth? _____________________________
Calculate where on the ecliptic you will find the Sun on your birthday and make a special light pencil mark there on the wheel.
- The Sun will be in what constellation on your birthday? _____________________________
T F 16. The Sun appears to spend the same number of days in each constellation of the zodiac.
T F 17. In the summer months, the Sun is lower near the horizon.
T F 18. The path of the Sun, Moon. planets and stars across our sky does not contradict the idea that they orbit the Earth and Earth is the center of the universe.
T F 19. A bright celestial object observed on the zodiac could be a planet.
Part 4: Movement of the Sun among the background stars: Analyzing Data (20 points)
|TABLE 3: Movement of the Sun through the Constellations|
|Date (2017-8)||Right Ascension
|Distance from the last position
(straight iine, in mm)
|Mar 20||0 hr 00 min||+ 0o||Distance per month|
|Apr 19||1 hr 50 min||+ 11o||26 mm|
|May 20||3 hr 50 min||+ 20o|
|Jun 19||5 hr 53 min||+ 23o|
|Jul 20||8 hr 00 min||+ 20o|
|Aug 19||9 hr 56 min||+ 13o|
|Sep 19||11 hr 48 min||+ 1o|
|Oct 19||13 hr 37min||– 10o|
|Nov 19||15 hr 41min||– 20o|
|Dec 19||17 hr 51min||– 23o|
|Jan 19||20 hr 07 min||– 20o|
|Feb 18||22 hr 05 min||– 12o|
|Mar 20||24 hr 00 min||– 0o|
- Carefully measure the distances between your pencil dots indicating solar position. Complete the last column of Table 3.
T F 21. The distance the Sun moves on the Star Wheel each month is always within 2 mm.
T F 22. The Sun appears to increase speed from September to January.
T F 23. The Sun appears to decrease speed from January to August.
T F 24. The Sun moves faster thru the sky Nov 19 – Dec 19 than Jun 19 – Jul 20.