General Astronomy, 29:61
Fall, 2005
Second Homework Set...September 2, 2005. Due September 9, 2005

Show calculations and give reasons for your answers. Don't go around confused and despondent; if you do not know how to get started, ask us for help. The purpose of problem sets is to promote thinking and lead to understanding, not produce a confiteor of revealed truth. Note: Data for many of these problems should be read from the SC1 chart.

(1) You are on a cruise ship in the Caribbean, having such a good time that you have no idea where you are. It is night, and you notice a very bright star due south, low above the southern horizon. Consulting your SC1 chart, you identify it as Canopus, $\alpha$ Carinae (leftmost quarter of the chart, in the bottom panel). It is on the meridian. You have brought along your string for measuring angular distances, and you measure the star's altitude angle as 20 degrees. What is your latitude?

(2) The star Altair (we saw it in lab this week) is one of the brightest stars in the sky. (It is on the right-center portion of the SC1 chart, near Right Ascension 20 hours). What is the altitude angle at transit of Altair here in Iowa City? The latitude of Iowa City is $41^{\circ}39^{'} (41^{\circ}.65)$.

(3) You have won a vacation to Quito, Ecuador! Obviously, it is on the equator. You are on the beach at 8PM on May 1. You see two very bright stars just about to set, due west out over the Pacific. Which stars are they?

(4) You are transported to a planet with an orbital period about its star of 4 months. The rotational period of the planet (=sidereal day) is 30 hours. What is the mean solar day on this planet?

(5) It is November 1. At what time of day or night does the bright star Rigel ($\beta$ Orionis, Right Ascension about 5 hours) transit?

(6) What is the declination of the southernmost star visible from Iowa City? Describe how you came up with your answer.

(7) On June 1, what is the angle between the Sun and the bright star Aldebaran ($\alpha$ Tauri)? For the purposes of this problem, you may measure the angle from the SC1 chart.

(8) It is midnight on January 3. What is the sidereal time? Name a bright star on the meridian.