29:52 Homework Set #1

Assigned: September 7, 2000

Due: September 14, 2000

Confused? Don’t go around miserable and despondent! Ask for help and explanation from me. Even better, work on these problems with one or two of your classmates.

1.The position of the planet Saturn is now RA=4^h 54^m, DEC= +20d47m. Describe where it is in the sky. That means, find out what constellation it is in, how close it is to any prominent stars, and where it is relative to the ecliptic and the celestial equator.

2.Approximately when will Saturn be up in the sky so you can see it? Describe your reasoning.

3.Imagine that there is a planet at a distance of 0.25 astronomical units from the Sun. It turns on its axis once in 24 hours. Is the difference between the mean solar day and the sidereal day greater than on Earth or less?

4.The island of Kauai (in the Hawaiian chain) is at a latitude of 22^°. How high above the northern horizon is the pole star Polaris?

5.Suppose you observe that Mars is at opposition. Four months later, what is the angle Ð Earth-Sun-Mars? Would you see Mars in the evening or morning sky? Hint: To do this problem, you will need data from Appendix 7 of your book. Second Hint: you may approach this problem graphically if you wish, drawing diagrams and making measurements with a protractor.