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(meteorobs) Re: Singing the Lyrids
Bruce and All,
I'm glad to have you point this fact out as I can only issue a "general"
report and not one for each region of the Earth. I find it fascinating that
conditions can vary so much. Please keep sharing your interesting
observations and insights with us!
Clear Skies!
Bob Lunsford (who was totally clouded out for the Lyrids)
----- Original Message -----
From: "Bruce McCurdy" <bmccurdy@telusplanetdot net>
To: <meteorobs@atmob.org>
Sent: Wednesday, April 23, 2003 5:35 PM
Subject: (meteorobs) Singing the Lyrids
> Hi folks, it's been a long winter since the Quadrantids, but once again my
> location high in the northern hemisphere led to moderately favourable
> conditions to observe the Lyrids.
>
> In his invaluable weekly meteor update, Bob Lunsford said:
>
> > The moon reaches its last quarter phase on Wednesday April 23. For this
> entire period the moon will be present in the morning sky, limiting the
> activity seen during this time of night.
>
> With the greatest of due respect to Mr. Lunsford, as a long-time lunar
> observer, lunar *avoider* (aka deep sky and meteor observer), and amateur
> orbital mechanic, I must point out that not all third quarter moons are
> created equal. Many/most of you know this already, including Bob himself
who
> is after all issuing global forecasts, but the local circumstances are
> always a point worth considering.
>
> The third quarter moon is in the spring, always near the lowest part of
the
> ecliptic; as experienced in "extreme" latitudes such as here in Edmonton,
> Canada (53.6 degrees north), this has a major delaying effect on moonrise.
> (In the southern hemisphere where it is now autumn, observers will have
been
> observing the Harvest Moon effect of an extremely high waning gibbous
moon.)
>
> Furthermore, we are approaching that point of the 18.6 year cycle known as
> the regression of the nodes (next maximum 2006) where the 5-degree tilt of
> the Moon's orbit is piggybacked atop Earth's own 23.4-degree inclination,
> resulting in some extreme declinations and, in the current instance, a
> further delaying effect on moonrise times.
>
> Net result was that on April 22, a gibbous moon still 26 hours before
third
> quarter phase was at -27 degrees DEC and did not rise here until 3:40 a.m.
> MDT, more than two hours after local midnight. I therefore was able to get
> in three hours of dark sky observation of the Lyrids in the morning hours,
> during which time the radiant soared from 32 to 57 degrees altitude.
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