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Fred Hebard wrote:

>
> 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.

Hello Fred,

Something is amiss here. If a point falls on a given line, it does so
regardless of the co-ordinate system. The ecliptic is fixed in the
horizontal (RA/Dec) system (ignoring minor and secular effects). Yes, the
declination of the Moon does change; but that's because the Moon follows
the ecliptic. Regulus does not change its ecliptic latitude of half a
degree, nor does the Moon change its own by more than 5 deg. If the Moon's
orbit were not inclined 5 deg w.r.t. the ecliptic, it would come within a
distance of Regulus equal to the size of its own semidiameter every single
month.

Best regards

Herbert Prinz

   

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