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Jonathan Ganz December 13th 05 11:53 PM

A real Navigation Question 1
 
In article .com,
Joe wrote:
Very good Jon,


Now follow orions belt in a curved line SE to Sirius you hit a nearly
equalateral triangle of Stars.


This is part of what constellation?


How many stars in this triangle are listed in the Nautical Almanac?

Name them..


I'd have to look it up.

--
"j" ganz @@
www.sailnow.com



Gary December 14th 05 12:08 AM

A real Navigation Question 1
 
Joe wrote:
Very good gaz.

Now follow orions belt in a curved line SE to Sirius you hit a nearly
equalateral triangle of Stars.

This is part of what constellation?

How many stars in this triangle are listed in the Nautical Almanac?
Name them..

Joe

Tough one, Orion (The Hunter), Sirius (one of the dog stars), is it
Canis Minor?

Joe December 14th 05 12:23 AM

A real Navigation Question 1
 
The triangle is in Canis Minor. Only one star in the triangle is listed
in the daily almanac. What is its name and where is it in the triangle?

Once you fine it keep heading the same direction from orions belt with
just a bit less curve in your path.

You will come to the second brightest star in the sky..Name it. What is
it's negative magnitude?

Joe


Gary December 14th 05 12:31 AM

A real Navigation Question 1
 
Jonathan Ganz wrote:
In article .com,
Joe wrote:

Very good Jon,


Now follow orions belt in a curved line SE to Sirius you hit a nearly
equalateral triangle of Stars.


This is part of what constellation?


How many stars in this triangle are listed in the Nautical Almanac?

Name them..



I'd have to look it up.

I'm in the look up phase too. When doing astro, my routine was (because
I don't do it anymore) to shoot the five or six first stars I saw at
twilight then whip out the star globe and figure out which they were
prior to running the calcs (marc St. Hilaire method)using HO 229 or 249.
That is how I was taught (pre calculator).

This constellation stuff is not navigation, it's astrology or astronomy
or something.


Of course my favourite fix was equal altitudes at lunch. Anyone know
what that is and why navigators like it?

Gaz

Donal December 14th 05 12:33 AM

A real Navigation Question 1
 

"Joe" wrote in message
ups.com...
Very good gaz.

Now follow orions belt in a curved line SE to Sirius you hit a nearly
equalateral triangle of Stars.

This is part of what constellation?


It depends ...


If you curve SouthEastwards, then you will meet Beta Monoceros, which is the
bottom right star of an equilateral triangle. Alternatively you might
come to another equilateral triangle in Canis Major which consists of
Wessen, Adhara and Aludra.


How many stars in this triangle are listed in the Nautical Almanac?
Name them..



No Idea!!! Good question.


I like to see BB squirming in the effluent of his ignorance. Well done!



Regards


Donal
--




Joe December 14th 05 01:29 AM

A real Navigation Question 1
 
You have to be able to ID stars to shot them.

Of course my favourite fix was equal altitudes at lunch. Anyone know
what that is and why navigators like it?


Gaz


The sun near local apparent noon appears not to change altitude,
sometimes for three minutes or more. The length of time of ambiguity is
related to the zenith distance between the observer and the sun---the
greater the distance, the longer the episode of ambiguity. During this
period it is not possible to know the exact moment of LAN, which means
that it is not possible to know the longitude of the boat, it being
dependent on accurate GMT.

If, however, you take a sextant shot well before noon, when the sun is
clearly increasing in altitude, then after noon reset your sextant to
precisely the same altitude and wait for the sun to come to the horizon
in your sextant, the time of local apparent noon will be precisely half
the time between the two sights of equal altitutude, added to the time
of the first sight. If several sets of equal altitudes are taken, an
average of the estimates of local apparent noon will be obtained.

The Admiralty Manual of Navigation devotes a chapter to equal
altitudes. I have used this technique over the years in long zenith
distances (46 degrees) and short (12 degrees), with excellent results.

Joe


Joe December 14th 05 01:34 AM

A real Navigation Question 1
 
Well Done Donal it is in Canis major, and you named the star.

Now find which is in the daily almanac

Once you find it keep heading the same direction from orions belt with
just a bit less curve in your path.

You will come to the second brightest star in the sky..Name it. What is

it's negative magnitude?

Joe


Gary December 14th 05 01:41 AM

A real Navigation Question 1
 
Joe wrote:
You have to be able to ID stars to shot them.

Of course my favourite fix was equal altitudes at lunch. Anyone know
what that is and why navigators like it?


Gaz


The sun near local apparent noon appears not to change altitude,
sometimes for three minutes or more. The length of time of ambiguity is
related to the zenith distance between the observer and the sun---the
greater the distance, the longer the episode of ambiguity. During this
period it is not possible to know the exact moment of LAN, which means
that it is not possible to know the longitude of the boat, it being
dependent on accurate GMT.

If, however, you take a sextant shot well before noon, when the sun is
clearly increasing in altitude, then after noon reset your sextant to
precisely the same altitude and wait for the sun to come to the horizon
in your sextant, the time of local apparent noon will be precisely half
the time between the two sights of equal altitutude, added to the time
of the first sight. If several sets of equal altitudes are taken, an
average of the estimates of local apparent noon will be obtained.

The Admiralty Manual of Navigation devotes a chapter to equal
altitudes. I have used this technique over the years in long zenith
distances (46 degrees) and short (12 degrees), with excellent results.

Joe

I used two sextants, one for the equal altitudes to give longitude and
the other for merpass and latitude. The easiest fix of the day!

Capt.Mooron December 14th 05 03:04 AM

A real Navigation Question 1
 

"Commodore Joe Redcloud" wrote in message

Any minute now the other half of Mooron Joe, who is known as Mooron Aerts,
is
going to chime in that Polaris is a brand of snowmobile.


Heh.... it's the choice of most Inuit in Kugluktuk!

CM



Joe December 14th 05 07:05 PM

A real Navigation Question 1
 
Since no one got it compeletly I will provide you the answers.

The pointers do point to polaris

If you follow orions belt in a curved line SE to Sirius you hit a
nearly
equalateral triangle of Stars in the canis minor constellation.



How many stars in this triangle are listed in the Nautical Almanac?

1

Name them.. Only Adhara the western most star of the triangle is in the
daily almanac

Keep heading in the same direction from Orion's belt and you will find
Canopus the second brightest star in the sky with a negative magnatude
of (-0.9)

Whats false about it?

Canopus is part of a triangle that cover the false southern cross.

Joe



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