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Re: [TowerTalk] And now for something completely different(TrueNorth)

To: "Jim Miller" <JimMiller@STL-OnLine.Net>,"Rajiv Dewan, N2RD" <n2rd@arrl.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] And now for something completely different(TrueNorth)
From: Jim Lux <jimlux@earthlink.net>
Date: Sat, 16 Sep 2006 20:30:58 -0700
List-post: <mailto:towertalk@contesting.com>
At 04:49 PM 9/16/2006, Jim Miller wrote:
>According to "true north", is the North Star really at 0.00 degrees from
>north?  Is it our actual "true north"?
>73, Jim

No. The north star makes a little circle about 1.5 degrees in 
diameter around the true north point. (RA 02 31 49.08, Decl +89 15 
50.8 in J2000 coordinates) so it's about 3/4 degree off celestial north pole.

More detail than you really want: http://www.cadastral.com/2006ephs.htm


>----- Original Message -----
>From: "Rajiv Dewan, N2RD" <n2rd@arrl.net>
>To: <towertalk@contesting.com>
>Sent: Monday, August 28, 2006 9:15 AM
>Subject: Re: [TowerTalk] And now for something completely different
>(TrueNorth)
>
>
> > The stick at high noon is a very good method and a lot more useful
> > than stars at night.  You do not have to live exactly at the time
> > zone meridian.  You just have to find the sunrise and sunset for
> > *your* location and date.  So here are the steps:
> >
> > 1.  Find the sunrise and sunset time for the location and day you are
> > going to do the experiment.  You can find that in your local
> > newspaper or visit
> > http://aa.usno.navy.mil/data/docs/RS_OneYear.html and type in the
> > state and city.   (For even greater accuracy and greater generality,
> > you can enter the exact latitude and longitude instead of using the
> > city/state combination)  The web site has the times in ST without the
> > daylight correction.
> > For example it lists the sunrise and sunset times are 0530 and 1852
> > EST for Rochester, NY on August 28, 2006.   With the daylight
> > correction the times are 0630 and 1952 EDT.
> >
> > 2.  Compute the mid point which is high noon for the day and location
> > specified.  The duration of the day is 19:52 - 06:30 = 13 h 22 min.
> > Half of that is 6h 41 min.  Adding that to 6h 30 min (sun rise time),
> > I get  1:11PM EDT.
> >
> > 3.  The shadow of a vertical stick (use a plumb line for greater
> > accuracy) at 1:11PM on August 28, 2006 at Rochester, NY points due
> > North.
> >
> > Regards,
> > Raj, N2RD
> >
> >
> > > Here we go again.
> > > This method only works for those who live exactly on the time zone
> > > meridian.
> > > Don
> > > N8DE
> > >
> > > J A Ritter wrote:
> > > Two sticks, one vertical, the other horizontal placed along the
> > > path of
> > > the
> > > shadow at high noon will show True North...
> > >
> > > 73,
> > > Jack W0UCE
> > > Website: www.w0uce.net
> > >
> > > ailman/listinfo/towertalk
> >
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
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