Extrasolar Planets: Homework 1

This homework must be submitted in hardcopy before 3:31 PM Thursday, Feb 5.

Problems marked with * are optional for undergraduate students.

Use any of the following to answer the questions:

  1. Pick 2 methods by which exoplanets can be discovered. Make a graph showing the number of planets discovered by the two methods over the period 1995 - 2015.
  2. Look at the names of the host stars. These names usually have the form of a prefix (such as "HD") followed by a number.
    1. What are the most common prefices? If a prefix is an abbreviation, write the full name. Provide a reference for each common prefix, if you can.
    2. Divide the planets into three groups: those discovered before 2000, between 2000 and 2009, since 2009.

    3. How does the mix of these most common names change from one time period to the next?
    4. (*) Why does the mix of name change? Be specific: connect the typical properties of stars in particular catalogs to the methods used to discover planets.
  3. Starting with Newton's Universal Law of Gravity and his three laws of dynamics, derive a relationship between the radius of a planet's orbit around its star, and the period of that orbit (aka Kepler's Third Law). You may assume that the planet is much less massive than the star, and that the orbit is circular.
  4. Bonus! Starting with Newton's Universal Law of Gravity and his three laws of dynamics, show that closed orbits are ellipses (aka Kepler's First Law).