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Timekeeping and the Celestial Sphere

Timekeeping and the Celestial Sphere

This series of webpages is part of a course, called Astronomy 161: The Solar System, offered by the Department of Physics and Astronomy at the University of Tennessee. This unit covers the constellations; the naming of stars, including the Bayer and Flamsteed naming systems; star maps; the celestial coordinate system; timekeeping, including an animation of the difference between sidereal and solar days; Gregorian, Roman lunar and Julian calendars; the seasons; precession; lunar orbit and phases; solar and lunar eclipses; and tides. There is also a lunar perigee and apogee calculator, and a calendar program which prints a calendar for any year.


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