Astronomy - Astronomy News       Directories      *The Solar System           Asteroids              Comets              The Earth            Mars

  Meteors & Meteorites      The Moon         The Planets               The Sun               Venus      *The Constellations     Cosmology

  Extrasolar Planets          Stars & Galaxies    *Astronomical Observatories           Calendars             Observers' Manuals

 Space Science -   Mars Exploration             Moon Exploration                  NASA                        Solar System Exploration

  Space Exploration              Space Science News         *International Space Station   Manned Space Flight

  Project Apollo       Project Gemini                  Project Mercury                          Space Shuttle

  The Messier Catalog.2006. <http://seds.lpl.arizona.edu/messier/>

   Star Journey. National Geographic. 1996-2007. <http://www.nationalgeographic.com/features/97/stars/>.

   Strobel, Nick.  Lives and Deaths of Stars.  Astronomy Notes.  <http://www.astronomynotes.com/evolutn/s1.htm>.

   Strobel, Nick.  Other Galaxies and Active Galaxies.   Astronomy Notes.  <http://www.astronomynotes.com/galaxy/s1.htm>.