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Re: (meteorobs) Moonlit Leonids
Dear Tony,
Crucial for moonlight observations is indeed a moist-free sky. Under good
conditions (not necessary at altitude, e.g. at sea-level in the Netherlands
it can happen too when there is an arctic air circulation, bringing clear
skies and dry air - but yes, altitude helps) and with not too faint meteors,
still a lot can be seen and actually reasonable limiting magnitudes reached.
I have occasionally observed in the past under full moon conditions with
limiting magnitudes approaching +6.0. In general, when the sky is clear and
moist-free, magnitude +5.5 should be possible. Whenever I see Limiting
magnitudes quoted for full moon conditions which are (well) below +5.0 while
reportedly the skies were quite clear, I reckon this is a classic case of
underestimating limiting magnitudes. I firmly believe the latter is a
psychological factor and not a physiological factor involved with moonlight.
People think Lm's cannot be high with moonlight, so they estimate low Lm's -
they don't try as well as under non-moonlight conditions perhaps. This is a
very odd phenomena I have noted over and over again. So: moonlight is a
hindrance, but reasonable sky conditions ARE possible if weather cooperates.
A tip is to try to hide the moon from direct vision, e.g. behind a wall,
tree, house or something like that. And take a part of the sky which is
opposite the moon. Those two really make a difference.
If the upcoming Leonids are anything like the two 2001 peaks, then plenty of
bright Leonids should still be visible. If they are not - well, then not of
course...
Marco Langbroek
Dutch Meteor Society
----- Original Message -----
From: "Dr. Tony Phillips" <phillips@spacescience.com>
To: <meteorobs@atmob.org>
Sent: Tuesday, May 07, 2002 12:33 AM
Subject: (meteorobs) Moonlit Leonids
> Hi everyone,
>
> I'm working on an article for the Science@NASA web site about the 2002
> Leonids, and I have some questions about meteor observing when the Moon
is
> full. I know there are members of this list with plenty of experience
> observing under such conditions, so I thought you might know the answers.
>
> (1) For a meteor shower with a Leonid-like population index, by what
factor
> will a full Moon reduce the number of naked-eye meteors?
>
> (2) How much could you hope to improve your limiting magnitude on a
Moonlit
> night by, say, moving from a sea-level site with moderate humidity to a
dry
> high mountain observing site ? (Assume that both sites are free of urban
> light pollution, but not free of lunar light pollution.)
>
> (3) Can you offer any tips in general for observers who want to reduce the
> effects of lunar interference during the coming Leonid storm?
>
> Any comments and/or answers would be much appreciated.
>
> regards, Tony
>
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