2102-D Star Finder plastic plates, 12" diameter, in sturdy case $85.00   ...item# 1841

2102-D Star Finder

The unit consists of a base plate (North Hemisphere on one side, South on the other), plus set of latitude plates. Use the Nautical Almanac to look up the GHA of Aries for the time of interest, then set the appropriate latitude disk on the base plate. Rotate the arrow on the latitude disk to the Local Hour Angle of Aries (which is GHA Aries - LonW or GHA Aries + LonE), and you then have in your hand a complete (quantitative) picture of sky around you. From the disk you can read numerical locations of stars and planets, sun and moon — for example, the star Antares bearing 187° true and 25° above the horizon. This is an invaluable device for celestial navigators, but also useful for more general star gazing. NEW! Your purchase of this 2102-D Star Finder now includes a free copy of The Star Finder Book, which describes in detail how to use this versatile device.. Note that all you need to set up this star finder is your known latitude and longitude and GHA of Aries from the Nautical Almanac. Since you need just this one number from the annual almanac, you could use a simple long-term almanac that would last for 40 years. Alternatively, you could compute the GHA of Aries yourself using the formula we present in the book Emergency Navigation. This formula is also presented in our online discussion of emergency navigation, with suggestions on how you can practice using it. 2102-D Star Finder instructions in Italian, compliments of Gianluigi Conti.