Astronomy Lab: Observing Stars and Constellations, Lab Reports of Earth Sciences

Download Astronomy Lab: Observing Stars and Constellations and more Lab Reports Earth Sciences in PDF only on Docsity! Starry Night Lab Nats 102, Spring 2006 Bechtold & Oppenheimer Due: Tuesday, Feb. 7, 2006 TYPE your answers. Diagrams and the table for Part V can be neatly hand-written. [Lisa points out that the North Star is useful for navigation] Homer: That's nice, Lisa, but we're not in astronomy class. We're lost in the woods. -The Simpsons Part I. Polaris, and how nearby stars move over a night. 0. Set Location = Tucson, and Time = tonight @ 8 pm. Use Find (Ctrl-F) to find Polaris (also called the North Star). Not coincidentally, you'll find it above the northern horizon. 1. Brighter stars look bigger in Starry Night. Find the star named Sirius, note how big it's shown, then go back to Polaris. Roughly how bright is Polaris compared to Sirius? ("brighter", "fainter", "same"...) 2. Run time forward (3000x works best) over 1 night and watch Polaris. (If you Find an object, Starry Night will keep it centered as time passes.) How would you describe Polaris' motion in the sky? 3. How would you describe the motion of other stars relative to Polaris? Explain and draw a simple diagram to illustrate. 4. Turn on Constellations (Labels and/or Stick Figures). Find Ursa Major, then find the Big Dipper within. Center on Polaris, run time forward over 1 night, & watch the Big Dipper. (Note: You may need to zoom out to see this. How can the Big Dipper help you find Polaris? Explain in 1 sentence and draw a simple diagram to illustrate. (Hint: Are there any sets of stars that always face Polaris?) [You might ask, "Why not just use the Little Dipper, since Polaris is actually in it? The answer is, the Big Dipper is much brighter than the Little, so it's easier to find.] 5. Based on what you've learned in this exercise, why do you think Polaris is important? 6. Change your LOCATION to anywhere in the southern hemisphere. Look South and run time over 1 night. Is there a bright South Star that doesn't move? 7. How can you locate the South Celestial Pole using the constellation The Southern Cross (aka Crux)? [The northern hemisphere is lucky to have Polaris, and the southern hemisphere is lucky to have the Southern Cross.] Part II. How the stars move during a night. 0. Set location = Tucson (click 'Home' under location). Set time to tonight at 8 pm. Set the Time Flow Rate to 3000x and run Starry Night for 24 hours. Do this a few times, looking at the East horizon, then West, then South using the appropriate icons on the toolbar. [You've already done North in Part I.] 1. In what cardinal direction do stars rise above the horizon? [Cardinal = North, South, East, or West] 2. In what cardinal direction do stars set [move below the horizon]? 3. In what direction does the sun rise? In what direction does it set? 4. [There's no write-up for this question, but you'll need the experience to answer #5.] Grab any ball (basketball, tennis, whatever) for this section. This is your Earth. Make a small pen dot to indicate the north pole (or use the inflation hole.) Place another dot roughly halfway between the North Pole and the Equator -- that's you. Pick a distant object to represent a star. Slowly turn your Earth, watching the "you" dot. At some point in the rotation, your "Star" won't be visible to you- dot. Then it should rise, be visible to you-dot, and then set (not be visible to you-dot.) THE STARS APPEAR TO MOVE THROUGHOUT THE NIGHT BECAUSE THE EARTH IS TURNING. THE SUN RISES AND SETS FOR THE SAME REASON. 5. Use your Earth-ball and your answers to questions II-1 and II-2 to answer this: Which way does the earth turn, clockwise, or counterclockwise? (From the perspective of someone standing over the North Pole.) 6. Are any stars or constellations always above the horizon from Tucson? Which ones? 7. Change your location to the North Pole. Are any stars or constellations always above the horizon here? Which ones? Part V. Venus. In this section we're going to see where the planet Venus will be in the sky over the next 12 months. Venus is the brightest object in the sky except for the Sun or Moon. (The visible light we see from Venus is actually sunlight reflected off Venus's thick clouds.) Because Venus is so bright, and because it moves quickly in the sky, it's been important to human mythology. 1. Where was Venus on July 19, 2005 at 7 pm? 2. When Venus is East of the Sun (East is LEFT on your screen) it's visible in the evening sky. Since objects move east to west because of the spin of the Earth (which is west to east), an object east of the Sun sets AFTER the Sun. In this case it would be called "an evening star". The opposite is true if Venus is west of the Sun, it would be visible just before dawn and would be "a morning star." So, quickly move from July 19, 2005 to April 19, 2006. Will Venus be an evening star or a morning star at the end? 3. We'd like you to find out some Venus information for the following dates: Aug. 19 2005, Dec. 19 2005, Jan. 19 2005, April 19 2005. If Venus is east of the Sun, so it's setting later than the Sun, please tell us three things: a) time of Sunset; b) time of Venus-set; c) how long Venus is up after sunset (subtract a from b). [Use 3000x speed to advance backwards or forwards to see setting times] If Venus is west of the Sun, so it's rising earlier, give us: a) time of Sunrise; b) time of Venus-rise; c) how long Venus is up before sunrise (subtraction again). Venus is so bright that if it's in the sky more than 1/2 hour after sunset or earlier than 1/2 hour before sunrise, it's very easy to see. 4) From July. 19, 2005 to July 19, 2006, in monthly intervals, tell me if Venus is a morning star, an evening star, or can't be seen. We'll define "can't be seen" as rising or setting within a half hour of the Sun. So you'll need a little table here. (hand-drawn is okay if neat.) Part VI. The Moon. 1. Do Find "moon". Set date = 2/1/2006 and time= 7 pm. Where is the moon? What phase is it (or how full is it?) 2. Move the date forward 1 day. Do this 13 times. Describe how the moon's phase and distance from the sun changes. 3. Set date = 1/7/2006, time=7 pm. What phase is the moon? Run the simulation until sunrise. Describe the moon's motion. What fraction of the night is it up? 4. Set date = 12/22/2005, time=7 pm. Run from 7 pm to 7:30 am, and describe the moon's phase and its motion. What fraction of the night is it up? [Note: it shouldn't be up yet, but it should rise in the night] 5. Set date= 12/25/2005, time =7 am. What phase is the moon? Run simulation until 7 pm. What fraction of the DAY is the moon up?