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#1
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posted to rec.boats.cruising,sci.astro.amateur
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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! A big thank you in advance. Cheers, John Nagelson |
#2
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posted to rec.boats.cruising,sci.astro.amateur
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"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! A big thank you in advance. Dunno where you can find them online but the 57 stars a Acamar Achernar Acrux Adhara Al Na'ir Aldebaran Alioth Alkaid Alnilam Alphard Alphecca Alpheratz Altair Ankaa Antares Arcturus Atria Aviar Bellatrix Betelgeuse Canopus Capella Deneb Denebola Diphda Dubhe Elnath Eltanin Enif Fomalhaut Gacrux Gienah Hadar Hamal Kaus Aust Kochab Markab Menkar Menkent Miaplacidus Mirfak Nunki Peacock Pollux Procyon Rasalhague Regulus Rigel Rigel Kent. Sabik Schedar Shaula Sirius Spica Suhail Vega Zuben'ubi and to make it 58 add Polaris which is seen as a special case. Eugene L Griessel Sex is not the answer. Sex is the question. 'Yes' is the answer. |
#3
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posted to rec.boats.cruising,sci.astro.amateur
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More importantly - can anyone list a website that explains:
1. how \ where to find those 57 stars and 2. how to use them for navigation I was only aware of polaris, the southern cross and orion's belt as navigational stars. |
#4
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posted to rec.boats.cruising,sci.astro.amateur
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Try http://www.nga.mil/portal/site/maritime/
Select "publications" then from the drop down list you can choose digital sight reduction tables, either air or marine. That may help. |
#5
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posted to rec.boats.cruising,sci.astro.amateur
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On Apr 4, 5:34 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. Index of Selected Stars - (West to East) http://www.angelfire.com/nt/navtrig/F1.html couldn't find the 173 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! A big thank you in advance. Cheers, John Nagelson |
#6
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posted to rec.boats.cruising,sci.astro.amateur
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"Jim" wrote:
More importantly - can anyone list a website that explains: 1. how \ where to find those 57 stars and 2. how to use them for navigation I was only aware of polaris, the southern cross and orion's belt as navigational stars. Astro Navigators would be pretty stuck with only those stars to guide them. You need a minimum of 3 stars, preferably widely spaced to get good angles of cut for a halfway decent position. Polaris can give you a pretty fair latitude on its own but not a longitude. And only in the Northern hemisphere. The Crux can give you a fair idea of where South is but only in the southern hemisphere. Eugene L Griessel Plan to be spontaneous tomorrow. |
#7
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posted to rec.boats.cruising,sci.astro.amateur
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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/ |
#8
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posted to rec.boats.cruising,sci.astro.amateur
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On Apr 4, 7:57 am, "Jim" wrote:
More importantly - can anyone list a website that explains: 1. how \ where to find those 57 stars and 2. how to use them for navigation I was only aware of polaris, the southern cross and orion's belt as navigational stars. When I was flying KC-135's in the '70's we used celestial navigation on overwater flights. IIRC you should be able to find the lists in either the Air Almanac (most likely) or the H.O. 249 sight reduction tables. Probably doesn't help the nautical guys any but I don't have any experience in that area. The ideal solution is to get a three-star fix. Each star shot gives you a single line of position (LOP) and a three-star fix (using stars spaced correctly in the sky) would give you three LOP's, and when plotted on a chart would form a small triangle. Your position should be somewhere inside that triangle, so the smaller the triangle the better. That, combined with your DR position you plotted from your last fix using best-known winds will give you a pretty accurate position. In the daytime, where only the sun (and maybe the moon) could be seen you would usually get only a single line of position. On an east-west flight that LOP would be a speed line in the morning/evening and a course line in the middle of the day. On a typical 6-8 hour flight from, say, Hickam AFB in Hawaii to Anderson AFB in Guam you'd get both over the course of a flight. Sometimes in the daytime you could see Venus through the sextant (we used a periscopic bubble sextant) but it could be a challenge. --Walt Bozeman |
#9
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posted to rec.boats.cruising,sci.astro.amateur
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On Apr 4, 8:57 am, "Jim" wrote:
More importantly - can anyone list a website that explains: 1. how \ where to find those 57 stars and 2. how to use them for navigation I was only aware of polaris, the southern cross and orion's belt as navigational stars. Get a copy of Bowditch The American Practical Navigator. Joe |
#10
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posted to rec.boats.cruising,sci.astro.amateur
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"Walt" wrote:
On Apr 4, 7:57 am, "Jim" wrote: More importantly - can anyone list a website that explains: 1. how \ where to find those 57 stars and 2. how to use them for navigation I was only aware of polaris, the southern cross and orion's belt as navigational stars. When I was flying KC-135's in the '70's we used celestial navigation on overwater flights. IIRC you should be able to find the lists in either the Air Almanac (most likely) or the H.O. 249 sight reduction tables. Probably doesn't help the nautical guys any but I don't have any experience in that area. The ideal solution is to get a three-star fix. Each star shot gives you a single line of position (LOP) and a three-star fix (using stars spaced correctly in the sky) would give you three LOP's, and when plotted on a chart would form a small triangle. Your position should be somewhere inside that triangle, so the smaller the triangle the better. That, combined with your DR position you plotted from your last fix using best-known winds will give you a pretty accurate position. In the daytime, where only the sun (and maybe the moon) could be seen you would usually get only a single line of position. On an east-west flight that LOP would be a speed line in the morning/evening and a course line in the middle of the day. On a typical 6-8 hour flight from, say, Hickam AFB in Hawaii to Anderson AFB in Guam you'd get both over the course of a flight. Sometimes in the daytime you could see Venus through the sextant (we used a periscopic bubble sextant) but it could be a challenge. And doing it in a fast aircraft one is really bedevilled by factors that us sailors thankfully don't suffer. Like the coriolus effect on the bubble in the sextant and postion lines many miles apart that have to be transferred with drift guessed at etc. At sea, given the right conditions, a bit of luck and lots of skill one could plot a position within half a mile. I hate to think what sort of error air navigators had! As they said in World War two - celestial navigation is best left to the birds! That's why electronic navigation aids were such a priority. Eugene L Griessel The basic delusion that men may be governed and yet be free. |
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