This site describes soft gamma repeaters. The author, Robert C. Duncan of the University of Texas at Austin, explains how these strange, physically-extreme stars form, and why they emit steadily pulsating X-rays with...

Students can find the world of college physics difficult at times, and it's always good to have a wide range of instructional materials on hand in case they need them. The University of Tennessee's Physics Department has...

This collection of lecture notes discusses the fundamentals of astronomy. The lecture notes review the topics of celestial mechanics, light, matter, planets, telescopes, the sun, stellar astronomy, stellar evolution,...

This collection of animations introduces students to planetary motions, gravitational effects, and the scale of astronomical distances. Students can view visualizations of Earth's changing seasons, circumpolar motion,...

This website, authored by Ricky Leon Murphy of Astronomy Online, is a collection of references, images, and information for general astronomy. This work covers topics from the basics of science and observation through...