| • | Above the Skies, An Exploration into Our Universe Through Animated Spectroscopy - A description at the layman level about the applications of spectroscopy in the investigation of the Solar System, with interactive diagrams |
| • | ADAF Theory - Accretion disk theory, mixing-length theory of convection, advection-dominated accretion flows. |
| • | AMASE - Astrophysics Multi-spectral Archive Search Engine - An online astrophysics catalog developed using object-oriented database technology to help researchers locate multi-mission data in the NASA archives. |
| • | Astronomy and Astrophysics for all... - you can find every thing you want on this topic in this site... |
| • | Astrophysical Data - A nice beginners collection of constants and other data, assorted in one page... Beginner level, with links to more advanced sites. |
| • | Astrophysics - E-Print archive since April of 1992. |
| • | Astrophysics and Astronomy - Introductory essays on astrophysics and astronomy. |
| • | Cambridge Relativity - Beginner's guide to all the basic concepts of Astrophysics written by active scientists at Cambridge University, UK. |
| • | Canadian Institute for Theoretical Astrophysics - Nationally supported research centre. Find out about current research, upcoming seminars and job opportunities. |
| • | Cause of the Characteristics of Quasars - Hypothesis which attempts to explain the characteristics of QSOs (Quasi-Steller Objects), a.k.a. quasars, as optical illusions created by gravitational lensing and other phenomena. |
| • | Contents - Accretion in astrophysics - active galactic nuclei, processes and dynamics. |
| • | Dyson Sphere - A list of frequently asked questions with answers. |
| • | Encyclopedia of Astronomy and Astrophysics - Comprehensive archive of explantory articles on all key Astrophysics topics, categorised and fully searchable; actively updated by the Institute of Physics. |
| • | Famous Astrophysicists - Profiles several prominent astrophysicists. |
| • | Fermilab Theoretical Astrophysics Group - Partially funded by a NASA Astrophysics Theory grant, find information about the group's past and future meetings. |
| • | Grand Challenge Problems in Computational Astrophysics - Research session at the Institute for Pure and Applied Mathematics (IPAM), Los Angeles, CA, USA; 7 March - 10 June 2005. |
| • | Gravity is Cool, or, Why our Universe is Hospitable to Life - Text of the 1999 Oppenheimer lecture at UC Berkeley given by professor Freeman Dyson on the origin of life and other subjects. |
| • | Hands-On Astrophysics - Offers educational products that help students understand basic astronomy concepts. |
| • | Hyperspace - Site devoted to hyperspatial theories. |
| • | Interdisciplinary Astrophysics Group - |
| • | Living Reviews in Solar Physics - A peer-refereed, solely online journal publishing invited reviews covering all areas of solar and heliospheric physics research. Published by the Max Planck Institute for Aeronomy, Katlenburg-Lindau, Germany. |
| • | Modified Newtonian Dynamics - Overview of a controversial theory which is not generally accepted by the astrophysical community. |
| • | NASA Astrophysics Data System - Search system for abstracts in astrophysics, planetary sciences and solar physics. |
| • | Network Generator - Generates astrophysical reaction rates online using an extended database. |
| • | Nuclear Astrophysics Data - An area for providing nuclear data for astrophysics calculations, such as nucleosynthesis, stellar evolution, the Big Bang, and super-nova dynamics. |
| • | Olber's Paradox Solved - A well know problem from astrophysics, Olber's paradox (Why is the night sky dark?), solved. As well as Newton's related Gravity paradox. |
| • | On the Formation of Planetary Rings - Paper presented in 1996 by L. A. Molnar and D. E. Dunn. |
| • | Physics 208 - Introduction to Astrophysics - Course offered via The Electronic University, an educational outreach server at the University of Oregon. |
| • | Physics Topics - Teaching Notes - Teaching notes on celestial mechanics, classical mechanics, and stellar atmospheres. |
| • | Red Shift by Photon Decay - Author explains how Hubble's red shift of starlight spectra results from photon decay, proportional to traveled distance. |
| • | SIMBAD Astronomical Database - The SIMBAD astronomical database provides basic data, cross-identifications and bibliography for astronomical objects outside the solar system. SIMBAD can be queried by object name, coordinates, other criteria (filters), and lists of objects. |
| • | Smithsonian Astrophysical Observatory - A research institute of the Smithsonian Institution headquartered in Cambridge, MA, where it is joined with the Harvard College Observatory (HCO) to form the Harvard-Smithsonian Center for Astrophysics (CfA). |
| • | Solar System - Celestial Mechanics - Presents ideas about the rotation of the sun and planets. |
| • | Space Physics Textbook - A free online textbook on space physics. |
| • | Temporal Annex - Information mostly on the fourth dimension and theoretical physics. |
| • | The Astrophysical Journal - Devoted to recent developments, discoveries, and theories in astronomy and astrophysics. |
| • | The Astrophysics Spectator - Articles published on this site cover current research in astronomy and astrophysics, describe our current understanding of astronomical phenomena, and comment on issues related to astronomical research. |
| • | The Electric Universe - Physics knows four forces; 20th-century scientists were convinced that one of those, the electric force, played no macroscopic role in the Universe; site explains why that is incorrect. |
| • | The NASA Astrophysics Data System - The Astrophysics Data System (ADS) is a NASA-funded project which maintains four bibliographic databases containing more than 4.0 million records: Astronomy and Astrophysics, Instrumentation, Physics and Geophysics, and preprints in Astronomy. |
| • | The Structure, Stability, and Dynamics of Self-Gravitating Systems - An interactive Astrophysics textbook from Louisiana State University. |
| • | The Titius-Bode Number Sequence Deciphered - An explanation of the Titius-Bode Law of planetary spacing. |
| • | THIS-Tuneable Heterodyne Infrared Spectrometer - THIS - instrument pages for the Tuneable Heterodyne Infrared Spectrometer developed by the University of Cologne. THIS is a transportable receiver designed for atmospheric and astrophysical observations in the mid infrared spectral region (7-28 µm). |
| • | Titius-Bode Law - Overview of the Titius-Bode Law. |
| • | University of Surrey - Department of Physics (Research) - University of Surrey abridged version of the book "Astrophysics" , with many links to relevant material on astronomy, astrophysics and cosmology. |
| • | WCRI WalkerScience - Examines several aspects of astrophysics including the big bang, origin of heavy elements and satellites, dark matter and dark energy. |
| • | You Be the Astrophysicist - Interactive site for learning about astronomy and astrophysics. |
