## Problem Set 1

The first two exercises in this problem set use the Starry Night software included as a CD with your book. The program may also be available on owlnet.

1. In Starry Night, turn on all the labels, all the guides, and show astronomical constellation boundaries (note you can turn daylight on and off using the right mouse button).

(a) [1 pt] Set the date to Feb 1, 2005, and move the display to show the SW horizon. Under 'location' are listed many US cities. Those in the states of PA, OH, IN, IL, and IA all have about the same latitude, but have different longitudes. These include Akron, Cincinnati, Cleveland, Chicago, Columbus, Dayton, Des Moines, Indianapolis, Philadelphia, Pittsburgh, and Toledo. For each of these cities find the time of sunset by advancing the Sun to the horizon until the ground goes dark. Create a table with the following information: City Name, latitude, longitude, and sunset time.

(b) [1.5 pt] Plot the longitude against the sunset times for all the cities. Explain any and all trends that appear in the plot.

2. (a) [1 pt] Find the next two times (to the nearest day is ok) where the Moon crosses the ecliptic. For these dates note if the Moon is in ascending node (going from below to above the ecliptic), or descending node (above to below). Note the RA and constellation of the nodes, and the lunar phase.

(b) [1 pt] For an eclipse to occur, what phase(s) must the Moon be when it is at a node? What months would you expect eclipses this year?

(c) [0.5 pt] Move the time to February of 2006 and repeat part a. Did the nodes move from February of 2005?

3. [2 pt] Problem 28, chapter 3 of KF (occultation of Jupiter).

4. [2 pt] Problem 42, chapter 4 of KF (geosync satellite).

5. [1 pt] Problem 46, chapter 4 of KF (asteroid, S=1.25yr).