Of the 100 billion or more galaxies visible through existing telescopes, most are either spiral or elliptical in shape and about one-fourth are irregular in shape. In addition to their shape, star systems can be further...

This website provides brief tutorials on spectroscopy, cosmology, galaxies, light pollution, solar system scale, the sun, stellar properties, telescopes, the history of astronomy, and stars. This site also contains a...

This Center, at the University of California, Berkeley, is dedicated to making space science information accessible to educators and public. Internet-based classroom resources for astronomy education in grades K-12 and...

This web page contains lecture notes about the early universe. It describes the conditions that allowed particles to evolve into large stars and galaxies. The information provided is well organized and it also provides...

Welcome to the NASA/IPAC Extragalactic Database (NED). It is built around a master list of extragalactic objects for which cross-identifications of names have been established, accurate positions and redshifts entered to...