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philharrington.net

this web site has been developed as an extension of the books and articles on and about amateur astronomy authored by phil harrington. topics cover choosing and using astronomical equipment, observing selected sky targets, information on solar and lunar eclipses, and much more.

opticalmechanics.com

There is a massive library of various microscopes, all designed for specific operations and functions. If you are involved in the metallurgy industry, you need a metallurgy microscope. You can find these types of microscopes in classrooms to teach new users how to study various metal materials or examine metal specimens on a job site

astro-tom.com

amateur astronomy reference and education source

skyandtelescope.com

In the news this week: Globular clusters have the detailed scoop on our galaxy's past, and a "heartbeat" black hole binary in the Milky Way has gone mysteriously dim.

losmandy.com

precision equatorial mounts, dovetail secondary systems and accessories

astroleague.org

Analemma Observing Program Coordinator: Douglas Smith 6032 S. Nantac Rim Dr. Tucson, AZ 85706 (520) 396-3233 Email: dsmith217@cox.net Introduction Just about everyone knows that the Sun’s altitude at culmination, the highest point above the observer’s horizon, varies throughout the year – higher in the summer, and lower in the winter. However, outside of navigators, cartographers and