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Subject: Re: Silicon Sea: Leg 72 -NEW
From: Michael Wescott (wescott_mike@XXX.XXX)
Date: Tue May 29 2001 - 10:08:54 EDT
Sam Chan wrote:
> For unknown body #1, the compass bearing was 349.7.
> Using Can Dead Man Vote Twice At Election, correcting from
> compass to true requires easterly variation and deviation be added to
> compass. The variation was 10dW and deviation was 1dE, totaling 9dW.
> With a compass bearing of 349.7 and subtracting 9d (since it is W)
> results in 340.7. There is nothing near that location in the sky.
>
> I noticed that if I added instead of subtracting the compass corrections,
> the location fits Polaris and Deneb, thus my initial question to you to
> check the compass bearing. I figured that you started off with true
> bearings and converted them to compass.
> On 26 May 2001, at 13:43, Michael Wescott wrote:
> > > > 6) What are the names of the two unknown bodies?
> > > > -- ---------------------------------------------
> > >
> > > Unknown #1:
> > >
> > > 349.7 + 10 - 1 = 358.7d
> > >
> > > almost due north and altitude is about same as our latitude:
> > > got to be Polaris
> >
> > Right
> >
> > > Unknown #2:
> > >
> > > 327.3 + 10 - 1 = 336.3
> > >
> > > This is visually in the angle between Polaris to the north and Vega
> > > to the northwest. GHA Aries is about 34d and Long is 67W so zenith
> > > has SHA of about 33d. Looking at the starchart in the almanac, there
> > > is only one navigational star between Vega and Polaris: Deneb
> >
> > Right
Hmmm. Good point. I just *knew* what the first one was, so I didn't think
too hard about the calculations. Two wrongs made it right :-)
--
Mike Wescott
Wescott_Mike@XXX.XXX
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