assignments

Observing Assignment #1

• Sketch the constellation Orion. When sketching stars, it is customary to use a larger, darker mark to indicate bright stars and a smaller, fainter mark to indicate fainter stars. Spend a good 15-20 minutes (plus) making your sketch. Try to draw the relative distances between the stars as accurately as you can. When you have finished with your sketch, go back inside and use whatever resources you want to mark the names of every star you can.

Observing Assignment #2

• Find Saturn in the night sky (rises in the east around 9pm these days) and sketch its location relative to the surrounding stars. Over the course of the semester return to this project and mark Saturn's trek across the celestial sphere. Be sure to mark each data point on your home-drawn map with a date and time. Before turning in your observing journal at the end of the semester be sure to write up an explanation in your own words for why Saturn moves in such a fashion.

Homework #1

• Please type up your solutions and bring a hard copy to class on Monday. Be prepared to discuss your answers. I'm expecting one or two paragraphs for each of these questions (written in complete sentences, of course). It doesn't have to be a lot, but it should be enough to convince me that you understand what you are writing and are not just copying ideas out of the book.
  • Why should you be sure to plot Absolute Magnitude or Luminosity & NOT Apparent Magnitude when you are making a HR Diagram? Can you think of any situation when plotting Apparent Magnitude would be acceptable?
  • Why are there more stars on the Main Sequence than in other areas of a typical HR Diagram?
  • Looking at Figure 4.8 in your book, how might you describe the distribution of masses in an HR Diagram? How might these masses have been determined? Can you come up with any logical story line that explains such a distribution of masses?
  • Explain what the "Main Sequence Turnoff" is and briefly describe what it can tell us about star clusters.
  • Briefly describe the effect of interstellar dust and gas on our observations of stars. Discuss possible corrections we can make to account for these effects.

• And one review question and some extra credit!
  • Explain why after the sun sets in Venezuela it gets very dark far quicker than it does here in Vermont. A pair of figures would be very helpful.
  • EXTRA CREDIT: You are at 42 degrees North latitude and the Local Sidereal Time is 0600h (which simply means that the line of 6 hours Right Ascension bisects your sky running from due North, through your zenith, all the way to due South). What is the Azimuth and Altitude of the star Sirius? Don't just look it up (though of course you can look up the RA and DEC of Sirius) Be sure to show me your work!

Observing Assignment #3

• Find Comet Lulin! It is near Saturn these days and has become a naked eye object on clear dark nights. You can find information and finder charts at Heavens Above (link on Resource page) under the Astronomy Section: C/2007 N3 Lunin. Keep an eye on it from night to night for the next week or so -- you can either put your observations on the same chart as you are keeping for Saturn, or you can create a new chart. Closest approach is in the early morning on Tuesday.

Homework #2

• Please type up your solutions and bring a hard copy to class on Monday. Be prepared to discuss your answers. I'm expecting one or two paragraphs for each of these questions (written in complete sentences, of course). It doesn't have to be a lot, but it should be enough to convince me that you understand what you are writing and are not just copying ideas out of the book.
• Read Chapter 5 of our book and answer the following questions:
  • Describe each of the various types of interstellar regions and for each think about how we might detect such a region from here on Earth. Which forms are most directly connected with star formation?
  • Table 5.1 is ordered in a very logical way -- What is it? Once you recognize the overall theme, walk me through each line of the table explaining its place in the storyline. Hint: Think about how these various regions are created!
  • Why doesn't every dense core of gas collapse into a star? Give a few possible reasons.
  • Check out the image of the Orion region here. Orion is tough to pick out, but is located behind the bright crescent of gas in the lower half of the image. Describe the various features you see throughout the image. Starting in the lower left of the image and continuing to the very top of the image is a fairly straight line of bright spots. What is that?

Observing #4

Observing #5

Quiz #1

Observing #6

Observing #7

• http://www.earthsky.org/article/earthskys-meteor-shower-guide
• http://meteorshowersonline.com/lyrids.html
• http://www.amsmeteors.org/index.html
• http://www.amsmeteors.org/showers.html#Lyrids