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.


Journal paper:  

   Reiss 2000,

   The Case for an Accelerating Universe from Supernovae,

   Publications of the Astronomical Society of the Pacific, 112, 1284





1.  Read the paper carefully.  Pay particular attention to the sources of uncertainty in

     the measurements of distances to Type Ia supernovae.


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

          something else.


    (ii)  Briefly describe any methods mentioned in the paper (or others that you may

           think of) to reduce this particular source of uncertainty.