Orbiting Binary Stars

Physical and Astronomical Constants

 Astronomy Hyper Text Book

 The Galaxy Gallery: Messier Objects

 Astronomy Picture of the Day Archive

 NASA/IPAC Extragalactic Database

 Space Telescope Science Institute home page

 SDSS home page

  NRAO home page

  ALMA project

 Keck telescope

 CO map of the Galaxy

 Schlegel, Finkbeiner, Davis (ApJ 500, 525) dust map

 Microwave Dust Emission

 H alpha map of the sky

 Skyview: a virtual observatory
 

 Introduction to Cosmology