Astronomy 122 Distance Education Second Homework Assignment

  1. The Hipparcos satellite was a parallax mission designed to greatly increase the numbers of stars with parallax measurements. Find out when this mission was flown, how many stars were measured, what the distance limit of the Hipparcos sample is compared to the ground based sample and whether or not there are any substantial changes to our view of the HR diagram as a result of these measurements. (Note we will be getting to this material later in the course).

  2. For main sequence stars, there is a relationship between their total mass and their energy output (which we call the luminosity). Find out what the form of this relationship was and how it was empirically discovered.

  3. Astronomers have recently discovered a new spectral type for stars. They are classified as Spectral type L. When were these stars discovered, how were they discovered and what kind of stars do they appear to be?

    These 2 questions are designed to test your knowledge of applying the inverse square law. (Play with the simulator that can be found at the bottom of the page in Lecture E, Module 1).

  4. Star A and Star B are identical. Star is located at distance of 1 light year from the observer and Star B is located at a distance of 10 light years from the observer. Star A deposits a total flux on the observer's detector of 100 units of energy per second. What is the flux on this detector from Star B? (Show your work)

  5. Suppose we now introduce a new star, Star C. Star C has an intrinsic energy output which is 10 times larger than Star A or Star B. Star C is at a distance of 4 light years from the observer. What is the flux that the observer detects from Star C? (Show your work)