Astronomy 490                                  Homework #11                                      Spring 2007



Due date:   Monday, May 7 at start of class.


Journal paper:  

   Luhman 2007, Discovery of Two T-Dwarf Companions with the

           Spitzer Space Telescope, Astrophysical Journal, 654, 570


Supplementary articles from Sky and Telescope Magazine:


  Waller 2003, NASA’s Space Infrared Telescope: Seeking Warmth in the Cosmos,

          February 2003


  Basri 2005, A Decade of Brown Dwarfs, May 2005


  Kaler 2000, Stars in the Cellar:  Classes Lost and Found, September 2000 (optional)



1.  Read the Waller and Basri Sky & Telescope articles first—they provide valuable

     background about the Spitzer Space Telescope (formerly known as “Space Infrared

     Telescope”) and brown dwarfs, respectively.  The Kaler article is optional, for anyone

     who would like to learn a little more about the history behind spectral types of the  

     stars, and the new additions of “L” and “T” spectra types.


2.  Read the Luhman ApJ article carefully.   Note that the abstract has purposefully been   

     omitted from the hardcopy provided.  If you need to download the paper from the

     web, please avoid reading the abstract J


3.  Write an abstract for the Luhman article.  (Hint:  remember that abstracts should

     summarize the key findings of a paper, including quantitative results whenever

     possible.  For observational papers, the abstract should also state what telescope and

     instrument was used and briefly describe the sort of data that were taken.) 


4.  In preparation for the final presentations, let’s collate everyone’s ideas about what

     makes a good presentation, following our class discussion last week.  Please email me

     your thoughts about the following:

         (i)  elements of a good presentation

         (ii)  things to try to avoid / watch out for

         (iii)  your suggestion for the smallest font that should be used in powerpoint  


     I will collate these ideas and suggestions and put them on the class web page.