National Aeronautics and Space Administration

VII. References and Other Resources

For additional activities using the Hubble Deep Field, see "Galaxies Galore" on Amazing Space, http://amazing-space.stsci.edu/

For additional information on active galaxies, see the Active Galaxy articles on Imagine the Universe!, http://imagine.gsfc.nasa.gov/science/objects/active_galaxies1.html

Planispheres may be purchased at any planetarium and many science museum shops. To make your own planisphere, see http://www2.washjeff.edu/physics/plan.html.

The galaxy images used in this booklet are from the Digital Sky Survey, as cataloged on the Interactive NGC Catalog Online

• http://www.seds.org/~spider/ngc/ngc.html

For other discussions of rotation curves and the evidence for dark matter, see

• http://astron.berkeley.edu/~mwhite/darkmatter/rotcurve.html

For additional discussion of dark matter, see

• http://www.physics.fsu.edu/courses/spring99/ast3033/darkmatter.htm

An excellent guide to observing the night sky with a small telescope is "Turn Left at Orion: A Hundred Night Sky Objects to See in a Small Telescope - And How to Find Them," by Dan M. Davis, Guy J. Consolmagno, Daniel M. Davis, Cambridge Univ Pr (Trd); ISBN:0521482119.