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Mike, you wrote:
"The slowest part is  tracking the two bodies together the first time. I have
done a series of Lunars  at 70 d separation and getting them together the
first time was a  challenge."

There are a couple of tricks you can use to speed this up.  First, get the
predicted distance. There's a tool on my web page that will given  you the
geocentric predicted distance, or you can calculate it yourself from the  GHA and
Dec from any other almanac source (it's just the great circle distance).  With
a little practice, you can even estimate the semidiameter corrections and  the
parallax/refraction corrections to give the distance you will actually
measure within a few arcminutes. Pre-set the sextant to that distance. Next, the
horns or cusps of the Moon's disk are aligned perpendicular to the line that
points to the Sun. Since (most of) the lunars stars and the planets are all
fairly close to the ecliptic, this line will also generally point to any object
you're trying to shoot for lunars. With the distance preset, you aim the
sextant  at the Moon and rotate until the horns are aligned perpendicular to the
frame of  the instrument. Almost every time, the object you're shooting will
pop right  into view. Note that a few of the traditional lunars stars --Altair,
Fomalhaut,  Markab-- may require you to rotate as much as 45 degrees away from
this standard  alignment but never more than that.

Both of the above tricks, presetting  the angle and aligning the horns
perpendicular to the frame, have been part of  the lunars method from the very
beginning. So there's no 'cheat' involved in  using them. Also, consider standing
somewhere so that you're target object is  close to some convenient terrestrial
mark, like the roofline of a building or a  phone line. Then you'll almost
never "get lost" hunting down the other object  for a lunar.

-FER
42.0N 87.7W, or 41.4N  72.1W.
www.HistoricalAtlas.com/lunars

   

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