list of 173 'navigational' stars?
 

But the saying " Worth his salt" refers to the amount of salt in your
body, not the amount of salt in your local lake.



That's incorrect. It refers to whether you are worth being paid, your
salt being your salary in the Roman legion. Of course, if you're an old
salt, that's another matter. :)

list of 173 'navigational' stars?
 

On Apr 5, 1:48 pm, "John Nagelson" wrote:
On Apr 4, 5:11 pm, " wrote:



On Apr 4, 2:34 am, "John Nagelson" wrote:

Hello, the US Nautical Almanac lists 173 "navigational stars", of
which a shorter list of 57 is sometimes extracted.

I've been unable to find these lists online, although I have found
databases referencing many millions of stars!

Could someone tell me if they know where the lists of 57 and 173 stars
exists online.

Or if it doesn't, and someone has got the two lists in text format,
I'd be very grateful if they could post them in follow-up to this
message!

Bowditch's THE AMERICAN PRACTICAL NAVIGATOR in hardcopy, or
online in PDF form at URL:

http://www.irbs.com/bowditch/

A big thank you to everyone who has posted in reply. Bowditch looks a
fantastic
source on celestial navigation, which I will study.

Unless I am mistaken, though, it gives the list of 57 plus Polaris,
not the 173, although it says the latter is given in the US Nautical
Almanac.

Maybe there is a shareware navigation program somewhere that I can
pick out the
info from???

The Nautical Almanac is not available online or in PDF form, but
there's a free (shareware) program with the data that can be printed.

Check these out:

http://www.tecepe.com.br/scripts/AlmanacPagesISAPI.isa
http://www.tecepe.com.br/nav/download.htm
http://www.tecepe.com.br/nav/TheOnlineNauticalAlmanac.htm

http://aa.usno.navy.mil/data/docs/Nav_Star_Chart.html
http://aa.usno.navy.mil/data/docs/navstarchart.pdf

http://www.nga.mil/portal/site/nga01/

http://www.celestialnavigation.net/

http://websurf.nao.rl.ac.uk/

list of 173 'navigational' stars?
 

On Apr 6, 2:52 am, " wrote:
On Apr 5, 1:48 pm, "JohnNagelson" wrote:





On Apr 4, 5:11 pm, " wrote:

On Apr 4, 2:34 am, "JohnNagelson" wrote:

Hello, the US Nautical Almanac lists 173 "navigational stars", of
which a shorter list of 57 is sometimes extracted.

I've been unable to find these lists online, although I have found
databases referencing many millions of stars!

Could someone tell me if they know where the lists of 57 and 173 stars
exists online.

Or if it doesn't, and someone has got the two lists in text format,
I'd be very grateful if they could post them in follow-up to this
message!

Bowditch's THE AMERICAN PRACTICAL NAVIGATOR in hardcopy, or
online in PDF form at URL:

http://www.irbs.com/bowditch/

A big thank you to everyone who has posted in reply. Bowditch looks a
fantastic
source on celestial navigation, which I will study.

Unless I am mistaken, though, it gives the list of 57 plus Polaris,
not the 173, although it says the latter is given in the US Nautical
Almanac.

Maybe there is a shareware navigation program somewhere that I can
pick out the
info from???

The Nautical Almanac is not available online or in PDF form, but
there's a free (shareware) program with the data that can be printed.

Check these out:

http://www.tecepe.com.br/scripts/AlmanacPagesISAPI.isa
http://www.tecepe.com.br/nav/download.htm
http://www.tecepe.com.br/nav/TheOnlineNauticalAlmanac.htm

Only uses 60 stars unfortunately!

http://aa.usno.navy.mil/data/docs/Nav_Star_Chart.html
http://aa.usno.navy.mil/data/docs/navstarchart.pdf

Already downloaded this and printed it - very nice chart
but shows the 57 with names and numbers, not the 173.

John

http://www.nga.mil/portal/site/nga01/

http://www.celestialnavigation.net/

http://websurf.nao.rl.ac.uk/

list of 173 'navigational' stars?
 

"John Nagelson" wrote:

Already downloaded this and printed it - very nice chart
but shows the 57 with names and numbers, not the 173.

I'm sure your life must be empty not knowing that the likes of Eta
Virginis, Delta Velorum and Beta Corvi and the like are also on rare
occasions used to navigate by. I could give the full list but really
think its pointless.

Eugene L Griessel

We do precision guesswork.

list of 173 'navigational' stars?
 

"John Nagelson" wrote:

On Apr 6, 2:52 am, " wrote:
On Apr 5, 1:48 pm, "JohnNagelson" wrote:





On Apr 4, 5:11 pm, " wrote:

On Apr 4, 2:34 am, "JohnNagelson" wrote:

Hello, the US Nautical Almanac lists 173 "navigational stars", of
which a shorter list of 57 is sometimes extracted.

I've been unable to find these lists online, although I have found
databases referencing many millions of stars!

Could someone tell me if they know where the lists of 57 and 173 stars
exists online.

Or if it doesn't, and someone has got the two lists in text format,
I'd be very grateful if they could post them in follow-up to this
message!

Bowditch's THE AMERICAN PRACTICAL NAVIGATOR in hardcopy, or
online in PDF form at URL:

http://www.irbs.com/bowditch/

A big thank you to everyone who has posted in reply. Bowditch looks a
fantastic
source on celestial navigation, which I will study.

Unless I am mistaken, though, it gives the list of 57 plus Polaris,
not the 173, although it says the latter is given in the US Nautical
Almanac.

Maybe there is a shareware navigation program somewhere that I can
pick out the
info from???

The Nautical Almanac is not available online or in PDF form, but
there's a free (shareware) program with the data that can be printed.

Check these out:

http://www.tecepe.com.br/scripts/AlmanacPagesISAPI.isa
http://www.tecepe.com.br/nav/download.htm
http://www.tecepe.com.br/nav/TheOnlineNauticalAlmanac.htm

Only uses 60 stars unfortunately!

http://aa.usno.navy.mil/data/docs/Nav_Star_Chart.html
http://aa.usno.navy.mil/data/docs/navstarchart.pdf

Already downloaded this and printed it - very nice chart
but shows the 57 with names and numbers, not the 173.

http://asa.usno.navy.mil/SecH/brightstars.html

Download the PDF file for one of the years. In it the names of some
stars are preceeded by a number - 1 to 173 will give you the stars you
want.

Eugene L Griessel

We do precision guesswork.

list of 173 'navigational' stars?
 

On Apr 6, 5:26 pm, (Eugene Griessel) wrote:
"JohnNagelson" wrote:
Already downloaded this and printed it - very nice chart
but shows the 57 with names and numbers, not the 173.

I'm sure your life must be empty not knowing that the likes of Eta
Virginis, Delta Velorum and Beta Corvi and the like are also on rare
occasions used to navigate by. I could give the full list but really
think its pointless.

Hi Eugene, you only had to ask and I would have said why I want
them :-)

I am a comparative anthropologist studying the history of maritime
star lore
in various parts of the world, including the west. This is such a wide-
ranging
subject, geographically and chronologically, that I am ruthlessly
restricting
the number of stars under consideration at the outset. Various
interesting stars
are outside of the 57, e.g. Algol (Beta Persei), and Mizar.
I wouldn't be at all surprised if I find material on the stars that
you
mention. Certainly the first and third look likely candidates, also
known
as Zaniah and Kraz.

If you could post the full list it would not fill up an empty life,
but it would be much appreciated.

John

list of 173 'navigational' stars?
 

* John Nagelson wrote, On 4/6/2007 12:32 PM:
On Apr 6, 5:26 pm, (Eugene Griessel) wrote:
"JohnNagelson" wrote:
Already downloaded this and printed it - very nice chart
but shows the 57 with names and numbers, not the 173.
I'm sure your life must be empty not knowing that the likes of Eta
Virginis, Delta Velorum and Beta Corvi and the like are also on rare
occasions used to navigate by. I could give the full list but really
think its pointless.

Hi Eugene, you only had to ask and I would have said why I want
them :-)

I am a comparative anthropologist studying the history of maritime
star lore
in various parts of the world, including the west. This is such a wide-
ranging
subject, geographically and chronologically, that I am ruthlessly
restricting
the number of stars under consideration at the outset. Various
interesting stars
are outside of the 57, e.g. Algol (Beta Persei), and Mizar.

Algol? Although relatively bright, Algol was omitted from the 57, I
believe because it is a variable star. In fact, it was recognized by
the ancients as variable, and known as the "Demon Star." (Algol and
Ghoul come from the same root.)

I have an affinity for the star because my first experience working in
astronomy was being on the team that discovered Algol was a strong
emitter of X-Rays.

list of 173 'navigational' stars?
 

On Apr 6, 9:38 am, "John Nagelson" wrote:
On Apr 6, 6:19 pm, (Eugene Griessel) wrote:



"JohnNagelson" wrote:
On Apr 6, 2:52 am, " wrote:
On Apr 5, 1:48 pm, "JohnNagelson" wrote:

On Apr 4, 5:11 pm, " wrote:

On Apr 4, 2:34 am, "JohnNagelson" wrote:

Hello, the US Nautical Almanac lists 173 "navigational stars", of
which a shorter list of 57 is sometimes extracted.

I've been unable to find these lists online, although I have found
databases referencing many millions of stars!

Could someone tell me if they know where the lists of 57 and 173 stars
exists online.

Or if it doesn't, and someone has got the two lists in text format,
I'd be very grateful if they could post them in follow-up to this
message!

Bowditch's THE AMERICAN PRACTICAL NAVIGATOR in hardcopy, or
online in PDF form at URL:

http://www.irbs.com/bowditch/

A big thank you to everyone who has posted in reply. Bowditch looks a
fantastic
source on celestial navigation, which I will study.

Unless I am mistaken, though, it gives the list of 57 plus Polaris,
not the 173, although it says the latter is given in the US Nautical
Almanac.

Maybe there is a shareware navigation program somewhere that I can
pick out the
info from???

The Nautical Almanac is not available online or in PDF form, but
there's a free (shareware) program with the data that can be printed.

Check these out:

http://www.tecepe.com.br/scripts/AlmanacPagesISAPI.isa
http://www.tecepe.com.br/nav/download.htm
http://www.tecepe.com.br/nav/TheOnlineNauticalAlmanac.htm

Only uses 60 stars unfortunately!

http://aa.usno.navy.mil/data/docs/Nav_Star_Chart.html
http://aa.usno.navy.mil/data/docs/navstarchart.pdf

Already downloaded this and printed it - very nice chart
but shows the 57 with names and numbers, not the 173.

http://asa.usno.navy.mil/SecH/brightstars.html

Download the PDF file for one of the years. In it the names of some
stars are preceeded by a number - 1 to 173 will give you the stars you
want.

Eugene L Griessel

Thank you very much, Eugene.

(I hadn't read the above post before I replied to your other one).

Unfortunately even this doesn't work, though!! I downloaded and
searched for
'150', '159', and '171' (chosen at random), and nothing came up -
so some of the 173 must be missing. Aarghh!

And some of the numbers appear multiple times, like 44.

There doesn't appear to be any online list of the 173. Given that
Bowditch is online (several places) I'm surprised the Nautical
Almanac is not. Since the list is readily available in the Almanac,
buy the almanac from the USGPO.

list of 173 'navigational' stars?
 

In article .com,
"John Nagelson" wrote:

Hello, the US Nautical Almanac lists 173 "navigational stars", of
which a shorter list of 57 is sometimes extracted.
...

Actually, the table that you found in the back of the Nautical Almanac
is NOT a table of the 173 "navigational stars".

It indicates which stars in the table ARE navigational stars by giving
their number. All 57 of them are there with their average SHA and Dec
for each of the 12 months of the year.

These particular stars were chosen as "navigational stars" based on
their brightness and the fact that their distribution on the celestial
sphere made them useful for establishing one's position. That's why
you'll find them listed on every one of the daily pages in the almanac.
These are the ones that navigators will normally use to determine their
position at sea - or in the air.

So what's with all the other stars listed in a table in the back of the
almanac called "Stars" (note that the title of the table is NOT
"Navigational Stars")?

What is listed in the Stars table is all the stars down to a magnitude
of 3.0 (and a few that are even dimmer). If a navigator was to bring
down a star, in all likelihood it would be in this range and thus in
this table.

When might one be called on to use the other 116 stars?

Well, at sea the sky is not always cloudless. If, through a break in the
clouds you find a star that would be great for getting a fix, you bring
it down and record the time of observation and the star's sextant
altitude. At this point, you then have the task of figuring out which
star it was so that, with it's SHA and Dec, you can determine the
corresponding LOP.

This is how you do that:

You work out your corrected altitude for the star and then determine
your DR position at the time of the sight. With this information, you
can then use a sight reduction table (or your calculator/computer
program) to determine the "calculated/estimated" SHA and Dec of that
star. Entering the Stars table, you can, with the calculated SHA, narrow
down the list of possible candidates for the star sighted and, with the
calculated Dec, determine the actual star that was brought down. If it
was one of the navigational stars, you go back to your daily page and
perform the usual ritual. If not, you simply extract the SHA and Dec
listed in the table for the actual star that you brought down and go
from there.

Now you know what that table is all about.

Lots of luck with your project.

ron

list of 173 'navigational' stars?
 

On Apr 6, 6:19 pm, (Eugene Griessel) wrote:
"John Nagelson" wrote:
On Apr 6, 2:52 am, " wrote:
On Apr 5, 1:48 pm, "JohnNagelson" wrote:

On Apr 4, 5:11 pm, " wrote:

On Apr 4, 2:34 am, "JohnNagelson" wrote:

Hello, the US Nautical Almanac lists 173 "navigational stars", of
which a shorter list of 57 is sometimes extracted.

I've been unable to find these lists online, although I have found
databases referencing many millions of stars!

Could someone tell me if they know where the lists of 57 and 173 stars
exists online.

Or if it doesn't, and someone has got the two lists in text format,
I'd be very grateful if they could post them in follow-up to this
message!

Bowditch's THE AMERICAN PRACTICAL NAVIGATOR in hardcopy, or
online in PDF form at URL:

http://www.irbs.com/bowditch/

A big thank you to everyone who has posted in reply. Bowditch looks a
fantastic
source on celestial navigation, which I will study.

Unless I am mistaken, though, it gives the list of 57 plus Polaris,
not the 173, although it says the latter is given in the US Nautical
Almanac.

Maybe there is a shareware navigation program somewhere that I can
pick out the
info from???

The Nautical Almanac is not available online or in PDF form, but
there's a free (shareware) program with the data that can be printed.

Check these out:

http://www.tecepe.com.br/scripts/AlmanacPagesISAPI.isa
http://www.tecepe.com.br/nav/download.htm
http://www.tecepe.com.br/nav/TheOnlineNauticalAlmanac.htm

Only uses 60 stars unfortunately!

http://aa.usno.navy.mil/data/docs/Nav_Star_Chart.html
http://aa.usno.navy.mil/data/docs/navstarchart.pdf

Already downloaded this and printed it - very nice chart
but shows the 57 with names and numbers, not the 173.

http://asa.usno.navy.mil/SecH/brightstars.html

Download the PDF file for one of the years. In it the names of some
stars are preceeded by a number - 1 to 173 will give you the stars you
want.

Does the ordering in the Nautical Almanac have a name?
I mean with Sirius at no.18, etc.
And could someone please enlighten me on the origin of the numbering.

Many thanks.

John