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Re: (meteorobs) Diffuse glow...

Detlef
That area would coincide with the anti-solar point around the time of
the shower. This would mean any glow would easily be confused with the
"gegenschein". Also in the days just before the shower the densest .01
AU area of the stream would appear so large in the sky as to be
extremely diffuse.
You might be interested in a chart I created on my web page
http://www.drdale.com/comets which shows the position of the stream
about a week prior to Earth's passage through it. I used comet and known
leonid meteor elements to created a stream which exactly intersects
earth's orbit (as do the actual impacting particles) and shows the
central 0.01 AU portion of the stream which D. Yeomans says contains the
highest concentration of particles. I really don't think anyone will see
a glow there but it is an interesting exercise. :)
Dale

Detlef Koschny wrote:
> 
> I remembered this one too, since it popped up just last week at the
> conference "Meteoroids 98" and the "International Meteor Conference 98" in
> Slovakia. The idea is that possibly the "glow" can be seen for the Leonids.
> It was mentioned in the article by Joe Rao "Perseids 1993: The big one?",
> WGN 21:3 (1993), pp. 110-119.
> 
> In the abstract it says: "Finally, a very rare phenomenon is briefly
> discussed: the prospect of actually detecting the particles producing the
> Perseid stream in interplanetary space just prior to or just after
> encountering the Earth". Later in the article he writes "My calculations
> indicate that just prior to when the Earth passes through the plane of the
> comets orbit, the stream of approaching meteoroids may show up as a glow
> roughly 10 deg to the south of Algol. The receding meteor stream would be a
> similar glow in the southern constellation of Triangulum Australe...".
> 
> I did not find any mentioning of the size of the glow or whether it would
> be better visible before or after the maximum.
> 
> My interpretation is that he only calculated in which direction the stream
> is. I am not aware of any real scientific study of this effect, i.e. to use
> the scattering properties of such particles (which is in itself a matter of
> debate) and integrate over the line-of-sight. This surely would be an
> interesting study for several streams. Anybody out there wants to make a
> thesis out of that? Let me know!
> 
> At last week's conferences, this glow was mentioned as one of the many
> interesting things to watch out for at the Leonid storm. Another
> interesting one is to look at the dark side of the Moon and try to detect
> impact flashes, which might be as bright as 6 mag...
> 
> Clear skies, Detlef.
> 
> At 01:45 PM 8/14/98 -0400, you wrote:
> >
> >> Lew... my tired brain is failing me at the moment... but I think it was in
> >> one of the WGN's I was reading down at Green Bank... ??
> >> I seem to recall that the glow was seen <before> an outburst, not after,
> ie.
> >> that it was a clue that something was coming!  The article gave an
> >> approximate size of the apparent cloud too, I thought...
> >> - Cathy
> >
> >Curioser and curioser, Cathy! :)
> >
> >Can one of our resident Human WGN Indexes confirm which issue this was in?
> >
> >Lew
> >
> >
> >
> >
> ----------------------------------------------------------------
> Detlef Koschny                      email: dkoschny@estec.esadot nl
> European Space Agency
> ESTEC Sci/SO
> Keplerlaan 1                              phone: +31-71-565-4828
> NL-2201 AZ Noordwijk ZH                     fax: +31-71-565-4697
> ----------------------------------------------------------------

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Dale Ireland 47.7N 122.7W
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