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Re: (meteorobs) Seeing the Geminids this year
Mike -
You wrote that if anyone wanted more times to write. I am in Phoenix, AZ,
any good times? (I found a very dark place out of town. Saw the Leonids
there).
Thanks,
Anna
>From: Mike Linnolt <mlinnolt@alum.mit.edu>
>Reply-To: meteorobs@jovian.com
>To: meteorobs@jovian.com
>Subject: Re: (meteorobs) Seeing the Geminids this year
>Date: Wed, 06 Dec 2000 20:26:14 -1000
>
>OOops! You are right Lew, I mistakenly thought Las Vegas was
>GMT-7 when its really in Pacific time, GMT-8 ! So, basically just
>subtract 1 hour from all of my "predictions" to get :
>
>1.) 1:40am night of Dec 13/14 (+/- a few hours)
>2.) 7:30pm - 8:30pm night of Dec 14/15
>3.) 1:40am night of Dec 14/15 (+/- a few hours)
>4.) 6:15pm - 7:15pm night of Dec 13/14
>5.) 1:40am night of Dec 12/13 (+/- a few hours)
>
>And, yes the 1:40am is based simply on radiant culmination.
>However, I think the "window" just before moonrise on Dec 14/15
>may turn out well. The mean radiant elevation during that hour is
>24° (at Las Vegas) and using the formula 1/Sin(elev) gives a rate
>reduction to about 40% of the rate if the radiant were at the Zenith.
>This will be fully compensated by lack of moonlight. (Its also a
>much better time of night for most folks in the middle of a work
>week! )
>
>Note: The exact timing of this window will vary substantially
>depending on your geographic location. For example:
>
>Miami, FL 8:20 - 9:20 pm
>New York City 7:25 - 8:25 pm
>San Francisco 7:50 - 8:50 pm
>
>If anyone wants the exact times for their location ,just send me a
>email privately.
>
>Cheers!
>Mike.
>
>
>On 6 Dec 2000, at 10:57, Lew Gramer wrote:
>
> > Mike, you make clear your reasons for the early evening times you
>mention
> > (times of moonrise, mainly). Although radiant elevation really does have
> > an unbelievable influence on observed rates (see IMO website or
>Handbook),
> > and the GEM radiant will be very low indeed during those hours, I have
>to
> > agree that the PROCESS of observing is more pleasant without the moon.
>:)
> >
> > However, what are the reasons behind your other predicted times? I
>haven't
> > heard any such detailed predictions of peak times for the GEMs -
>especially
> > because, as you say, the peak times are generally so broad for this
>shower.
> > Are these simply radiant culmination times? I doubted that, as they are
>an
> > hour too late for that. Just curious, thanks for any info.
> >
> > Clear skies!
> > Lew Gramer
>
>
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