Re: (meteorobs) Re: FWD: [Query re: Leonids and Draconids]
Lew Gramer wrote:
> The event you're probably describing is the "Leonids", a meteor shower which
> occurs every year in mid-November. What's special about their apparitions in
> 1998 and 1999, is that a "meteor storm" is predicted to POSSIBLY occur during
> the shower: in other words, a brief period when the normal 10-50 meteor per
> hour suddenly shoots up to 10-10,000 meteors per SECOND, and the sky appears to
> literally "fill with falling fire"!
10,000 meteors per second is a number too high. The known storm with the
higher rate was 1966 Leonids, with ZHR=150,000, that is about 42 meteors
per second. It is worth to note that Jenniskens (Jenniskens P.: Meteor
stream activity II - Meteor outbursts, Astronomy and Astrophysics, vol.
295, 1995, pp. 206-235) rose some doubts on this ZHR evaluation, that
does not find a consideration in radar data. According to Jenniskens,
the correct value should be ZHR=15,000, that is 4 meteors per second.
If I remember well, according to Wu and Williams (I do not have their
paper at hands), for 1998-1998 Leonids a ZHR=100,000 is expected. But
you have to take into account that there are large uncertainties in
dr. Luigi Foschini
CNR - Institute FISBAT
Via Gobetti 101, I-40129 Bologna (Italy)
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