This web page, authored and curated by David P. Stern, outlines the math and applications of parallax. Parallax is the shift in the apparent direction to an object when it is viewed from two separated locations. It...

This software for Windows, from Project CLEA -- Contemporary Laboratory Experiences In Astronomy, presents students with a radio telescope. The default operating characteristics (beam width, receiver noise, steerability)...

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...

This is a series of web pages on the Earth's Moon. It includes information about the Moon as observed by the eye from Earth, its orbital period, its phases, appearance and the reason it always presents one face, There is...

The first of four linked files, created by David P. Stern, giving a very brief and elementary overview of sunspots, flares and coronal mass ejections, including some early history and the articles by Schwabe (1843) and...