Astronomy 490 Homework #6 Spring 2007
Due date: Monday, March 19 at start of class.
Please make a copy of your assignment to refer to during the class discussion.
1. Read the paper carefully. Pay particular attention to the sources of uncertainty in
of distances to
2. List as many sources of uncertainty in the distance measures that you can find in the
paper. (Feel free to also add any other sources of uncertainty you may think of.)
Write a very short (e.g., 1-2 line explanation) of the nature of each source of error.
3. For each source of uncertainty you have identified:
(i) Briefly explain whether you think it is a random error, systematic error, or
(ii) Briefly describe any methods mentioned in the paper (or others that you may
think of) to reduce this particular source of uncertainty.