ISP 205 Lab 9 Discussion Questions

  1. Why did you need to measure the brightness of both the variable star and a companion star in this lab?

  2. The star Procyon in Canis Minor (the small dog) is a prominent star in the winter sky, because its apparent magnitude is +0.37. It is also one of the nearest stars, being only 3.51 parsecs from Earth. What is the absolute magnitude of Procyon? How many times brighter (or dimmer) than the Sun is it?

  3. Suppose two stars have the same apparent magnitude, but one star is ten times farther away than the other. What is the difference in their absolute magnitudes?

  4. A certain type of variable star is known to have an average absolute magnitude of 0.0. Such stars are observed in a particular star cluster to have an average apparent magnitude of +16.0. What is the distance to that star cluster?

  5. If the Sun were a variable star with the same amplitude (magnitude difference between maximum and minum brightness) variation as the star you measured in this lab, would you be able to observe that brightness variation with your naked eye?

  6. Astronomers also observe stars, the gas between stars, galaxies and quasars using radio telescopes. What advantages and disadvantages can you think of (given your experience with an "observatory" today) to observing in radio frequency rather than visible light? In visual we have to consider things like light pollution and cloud cover, etc. What do we need to take into account with radio?

Updated: 2002.09.11 (Wednesday) 10:13:05 EDT