Astronomy Links
Stellar Evolution Stellar Evolution is part of a hypertextbook on Astronomy under development at the University of Oregon. Planetary Nebula images at the National Optical Astronomy Observatory. Virtual Trips to Black Holes and Neutron Stars allows you to experience the unusual effects that occur near high-gravity objects. These images from radio telescopes in Europe and the U.S. show a scene of utter violence in the expanding shell of debris from Supernova 1993J in the galaxy M81.