In response to the 
2006 Astro phenomena list  Mark wrote to me:


I can only offer one minor suggestion: The usage of the term
"greatest brilliancy" -- which you show for Venus on 17 February --
is being phased out in astronomical ephemerides.  The term no
longer appears in the _Astronomical Almanac_, published jointly by
the U.S. Naval Observatory and the U.K. Nautical Almanac Office,
beginning with the 2006 edition.

Why so?  Sadly, the term was a mistake from the beginning, which
dates back to the late 1800s.  "Greatest brilliancy" is *not*
synonymous with "greatest magnitude" (though most people think
these two terms are equivalent); in the case of Venus, however,
"greatest brilliancy" and "greatest magnitude" always happen
within a couple days of one another, thus compounding the confusion
brought about by dubbing the event with the word "brilliancy."
A better example is Mercury, for which the times of "greatest
brilliancy" sometimes occur more than *two weeks* from the instant
of "greatest magnitude."

So what should be substituted for "greatest brilliancy"?  If you're
interested in the moment when Venus is brightest, then you can determine
when its magnitude function has reached a minimum -- the instant of
"greatest magnitude"; Guy Ottewell's _Astronomical Calendar_ is the
only publication I know of that reports this value for Venus.  The
other option is to report the moment when the planet's sunlit disk
has maximum apparent area -- the so-called instant of "greatest
illuminated extent" (GIE); both the _Astronomical Almanac_ and _Sky and
Telescope_ now report GIE routinely instead of "greatest brilliancy."
(Ottewell also reports GIE, in addition to "greatest magnitude," but
he prefers to call it "maximum illuminated area.")

These changes were brought about by the publication of the following
recent article:

    "Superior Moments for Inferior Planets."  _Sky and Telescope_
     May 2001, pp. 62-66.

which goes into much more detail.


Regards, Mark

THANKS to 

Mark Gingrich


THANKS MARK!!!!



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