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

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

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

Joe wrote:

The two second magnitude stars that form the outer part of the bowl of
the big dipper are often called the pointers. Why?

'Cos they point at Polaris.


--
Capt Scumbalino