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Re: (meteorobs) Unusual QUA activity before the predicted peak?
----- Original Message -----
From: "Lew Gramer" <dedalus@alum.mitdot edu>
> These are extraordinary numbers of Quadrantids, for observations many
hours
> before the predicted peak, aren't they?
[snip]
>
> But I have always labored under the impression that outside of a few hours
> of true "peak" time, the QUAs are a really *minor* shower of 1-3 per hour!
Hi Lew and others,
If you look at the activity profile we published for the Quadrantids, you'll
note the following: the Quads consist of a sharp 'main peak' superposed on a
more shallow background. If you look at the profile in terms of duration and
ZHR's, then:
- activity is above ZHR=20 for about 23 hours centered on the main peak;
- activity is above ZHR=10 for about 1.7 days;
- activity is above ZHR=5 for about 3 days.
So Lew: these rates or not that extraordinary for observations late during
the night (=high radiant altitude) for the given hours away from the
maximum, and rates do not drop below 5 for 1.5 days around either side of
the maximum, instead of 'a few hours'.
- Marco Langbroek (DMS)
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