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Fred Hebard's letter was fine, until he got to-

>The moon's declination changes radically from day to day, so the
>ecliptic is only a first approximation as to the best location for a
>star.  You could pick Regulus, which is smack dab on the ecliptic, and
>still have it be 35 degrees of declination out of the moon's orbit.

Not so, Fred. The Moon stays within about 5 degrees of the Ecliptic, even
though the Moon declination can change greatly over a month. Some years, it
can swing nearly 29 deg North and South of the Equator, in the course of a
month. It's not the declination that matters, though. Regulus, being so
close to the ecliptic, can never be more than about 7 deg North or South of
the Moon's path, as it passes Regulus. As long as Moon-Regulus observations
are made with a distance between them exceeding 20 deg or so, the speed of
the Moon approaching Regulus or leaving it will be quite adequate.

The Sun, by definition, is always on the ecliptic, so the Moon will always
be within 5 deg or so of the Sun, as it passes.

Other navigational planets will also be near the plane of the ecliptic:
Venus can't get more than 8 deg away, Mars, Jupiter, and Saturn closer
still. So it can be assumed that these bodies, like the Sun and Regulus,
are always suitable candidates for a lunar distance, as long as the lunar
distance exceeds 20 deg or so.

The "standard" list , from which would be selected appropriate stars to
provide lunar distance in the almanac on a particular day, was-

Altair, Fomalhaut, Hamal, Aldebaran,Pollux, Regulus, Antares, Spica, and Markab.

George.



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