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/

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???

Cheers,

John

"John Nagelson" wrote:

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???

Any visible star can be used for navigation. The 57 given in
Alamanacs are all bright stars which are not easily confused with
others. The majority of the 173 you will find are sometimes pretty
iffy and any celestial navigator would probaly only resort to them in
fairly awkward circumstances. When you start hitting 3 magnitude and
higher it gets more awkward to distinguish the star one wants from the
background - especially on a ship which may be moving quite heavily.
Brown, for instance, (In the last copy I bought) gives some stars up
to 4 magnitude. But practically, unless you are that rarest of
navigators who can distinguish 173 stars with certainty, anything much
higher than 2 magnitude becomes chancy. Wheras the SHA and Dec of the
57 principal stars are given on the daily pages of nautical almanacs I
don't think I have ever seen the lesser stars listed thus. They are
usually confined to a couple of pages in the back giving the SHA and
Dec for the month only. In principle, unless you plan to sail the
world, you could probably get away with an intimate knowledge of about
sixteen stars in your hemisphere.




Eugene L Griessel

For every person willing to teach, there are 30 not willing to be
taught

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/

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/

"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.

"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.

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

On Apr 7, 4:19 am, Ronald Wong wrote:

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".
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).

Many thanks Ron!

I got a list of the 173 brightest from:

http://www.atlasoftheuniverse.com/stars.html:

They are mostly under common names, but at least some of those that
aren't,
have got common names, e.g. Theta Aurigae is Bogardus, and Upsilon
Carinae
is Vathorz Prior.

====================

1. Sirius
2. Canopus
3. Rigil Kentaurus
4. Arcturus
5. Vega
6. Capella
7. Rigel
8. Procyon
9. Achernar
10. Betelgeuse
11. Hadar
12. Altair
13. Acrux
14. Aldebaran
15. Antares
16. Spica
17. Pollux
18. Fomalhaut
19. Deneb
20. Mimosa
21. Regulus
22. Adhara
23. Castor
24. Shaula
25. Gacrux
26. Bellatrix
27. Elnath
28. Miaplacidus
29. Alnilam
30. Alnair
31. Alnitak
32. Alioth
33. Mirfak
34. Dubhe
35. Regor
36. Wezen
37. Kaus Australis
38. Alkaid
39. Sargas
40. Avior
41. Menkalinan
42. Atria
43. Alhena
44. Peacock
45. Koo She
46. Mirzam
47. Alphard
48. Polaris
49. Algieba
50. Hamal
51. Diphda
52. Nunki
53. Menkent
54. Alpheratz
55. Mirach
56. Saiph
57. Kochab
58. Al Dhanab
59. Rasalhague
60. Algol
61. Almach
62. Denebola
63. Cih
64. Muhlifain
65. Naos
66. Aspidiske
67. Alphecca
68. Suhail
69. Mizar
70. Sadr
71. Schedar
72. Eltanin
73. Mintaka
74. Caph
75. Epsilon Centauri
76. Dschubba
77. Wei
78. Men
79. Eta Centauri
80. Merak
81. Izar
82. Enif
83. Girtab
84. Ankaa
85. Phecda
86. Sabik
87. Scheat
88. Aludra
89. Alderamin
90. Markeb
91. Gienah
92. Markab
93. Menkar
94. Han
95. Al Nair al Kent.
96. Zosma
97. Graffias
98. Arneb
99. Delta Centauri
100. Gienah Ghurab
101. Ascella
102. Zubeneschamali
103. Unukalhai
104. Sheratan
105. Zubenelgenubi
106. Phact
107. Theta Aurigae
108. Kraz
109. Ruchbah
110. Muphrid
111. Ke Kouan
112. Hassaleh
113. Mu Velorum
114. Alpha Muscae
115. Lesath
116. Pi Puppis
117. Kaus Meridionalis
118. Tarazed
119. Yed Prior
120. Aldhibain
121. Theta Carinae
122. Porrima
123. Hatysa
124. Iota Centauri
125. Cebalrai
126. Kursa
127. Kornephoros
128. Delta Crucis
129. Rastaban
130. Cor Caroli
131. Gamma Lupi
132. Nihal
133. Rutilicus
134. Beta Hydri
135. Tau Scorpii
136. Kaus Borealis
137. Algenib
138. Turais
139. Beta Trianguli Australis
140. Zeta Persei
141. Beta Arae
142. Choo
143. Alcyone
144. Vindemiatrix
145. Deneb Algedi
146. Head of Hydrus
147. Delta Cygni
148. Tejat
149. Gamma Trianguli Australis
150. Alpha Tucanae
151. Acamar
152. Albaldah
153. Gomeisa
154. Pi Scorpii
155. Epsilon Persei
156. Alniyat
157. Albireo
158. Sadalsuud
159. Gamma Persei
160. Upsilon Carinae
161. Matar
162. Tau Puppis
163. Algorel
164. Sadalmelik
165. Zaurak
166. Alheka
167. Ras Elased Australis
168. Alnasl
169. Gamma Hydrae
170. Iota Scorpii
171. Deneb el Okab
172. Beta Trianguli
173. Psi Ursae Majoris

====================

From what you say, a few of the above don't make it to the Nautical
Almanac list,
and a few that aren't above do!

Looking forward to delivery of my copy of the NA from Amazon :-)

John

In article .com,
"John Nagelson" wrote:

...
I got a list of the 173 brightest from:

http://www.atlasoftheuniverse.com/stars.html:

They are mostly under common names, but at least some of those that
aren't,
have got common names, e.g. Theta Aurigae is Bogardus, and Upsilon
Carinae
is Vathorz Prior.

====================

1. Sirius
2. Canopus
3. Rigil Kentaurus
...
154. Pi Scorpii
155. Epsilon Persei
156. Alniyat
157. Albireo
158. Sadalsuud
159. Gamma Persei
160. Upsilon Carinae
161. Matar
162. Tau Puppis
163. Algorel
164. Sadalmelik
165. Zaurak
166. Alheka
167. Ras Elased Australis
168. Alnasl
169. Gamma Hydrae
170. Iota Scorpii
171. Deneb el Okab
172. Beta Trianguli
173. Psi Ursae Majoris

If you've ever wondered why greek letters are part of a star's name - as
well as the naming of stars in general - take a look at:

http://www.astro.uiuc.edu/~kaler/sow/starname.html

ron