[Prev][Next][Index][Thread]
Re: (meteorobs) Moonlit Leonids
----- Original Message -----
From: "Os, Daniel van" <dvos@Strukton.com>
To: <meteorobs@atmob.org>
Sent: Tuesday, May 07, 2002 12:51 AM
Subject: RE: (meteorobs) Moonlit Leonids
> Dear Tony,
>
> > (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?
>
> The first problem here is what is a Leonid-like population index? The
value
> for the normal activity is 3 - 3.4. During the outbursts it can/will be
> different and it will vary during the peak. Last year the value was about
> 1.7 around the peaks and up to about 2.2 during the peaks, for now I'll
> assume 2.0.
>
> A limiting magnitude of 5.0 should certainly be possible in the right part
> of the sky. This would mean that the number of visible meteors would be
> reduced by a factor of 2.0^(6.5-5.0) = 2.8 compared to a mag 6.5 sky.
>
> Considering the low altitude of the moon (if you are in the right
location)
> I would not be surprised if an LM of 5.5 can be achieved, resulting in a
> factor of 2.
>
> So, a reduction factor of about 2 to 3.
>
> > (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 ?
>
> This would ceratinly improve things, though I'm not able to say how much.
> Not only will this reduce the lunar interference, but also the sky closer
to
> the horizon will be darker.
>
> > (3) Can you offer any tips in general for observers who want
> > to reduce the effects of lunar interference during the coming Leonid
> storm?
>
> For the first peak, at 4 UT, in Western Europe the moon will be quite low
> above the horizon (while twilight is approaching). At 10:30 UT, during the
> second peak this will be the same for the Eastern US I think (if Boston is
5
> hours behind UT). Too far to the east might not be good though. In Boston
> twilight will begin before the predicted peak time. Maybe Kansas, during
the
> peak the moon is 21 degrees above the horizon with an hour to go before
> twilight. Anyway, you'll have to find a latitude where the moon is as low
as
> possible, but where you'll still have some time before twilight.
>
> While observing keep the moon behind you. An observing site where you have
a
> clear view to the east but some obstruction hiding the moon in the west
> could help.
>
> Yours,
>
> Daniel van Os
> The archive and Web site for our list is at http://www.meteorobs.org
> To stop getting all email from the 'meteorobs' lists, use our Webform:
> http://www.meteorobs.org/subscribe.html
The archive and Web site for our list is at http://www.meteorobs.org
To stop getting all email from the 'meteorobs' lists, use our Webform:
http://www.meteorobs.org/subscribe.html
References: