Observing Tools
Clear Sky Chart Collimation Lunar Ephemeris Sunrise/Moonrise Data
Find the coordinates of your observing site with TOPOZONE.COM.
Synchronize your GOTO scope's computer with the atomic clock. Click on this link and then click on the "Java Display" link.
Download this Lunar Colongitude calculating program. Save it to your desktop.
Lunar Ephemeris
Ephemeris - (def.) a table giving the computed positions of a
celestial body for every day of a given period.
Important ephemeris calculations include Libration - (def. a slight
rocking motion of the moon which allows 59% of the moon's surface to be visible
from the earth), and colongitude (The lunar longitude of the morning
terminator i.e. the longitude on the moon of the lunar sunrise.).
Libration is given as the longitude and latitude of the apparent center of the
moon's disk. Colongitide is used to determine where the sun is at a low
angle giving long shadows which enhance features on the moon. The evening
terminator is the colongitude plus or minus 180 degrees.
Download a neat little lunar ephemeris program in a few minutes that you can use on your own computer. Download.
Or you can use this form.
This page copied with revisions from http://www.stargazing.net/kepler/jsmoon.html
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Collimation is a process of aligning the mirrors in a telescope so that the image can be focused as well as possible. This is a site that offers collimation tools for classical cassegrain and Newtonian reflector telescopes.