The Nautical Almanac of the stars - 2012

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 The Nautical Almanac of the stars (excel spreadsheet software year 2012) generates essential data needed for the pratice of celestial navigation - The freeware software  creates daily pages (printable sheet - A4). All these astronomical data and information allow mariners to calculate the ships position with the traditional method of the celestial navigation ( using a sextant ).

description of  the nautical almanac ( astronomical almanac for mariners )

The user must enter the date ( day - month ) and the geographical coordinates (latitude and longitude) of the  estimated position (to obtain the Greenwich Mean Time of the astronomical events : twilight, sunrise and sunset).
view of the The Nautical Almanac of the stars  pdf
The excel spreadsheet (software) shows :
Sun  :  Greenwich hour angle (G.H.A.) and  declination tabulated at hourly intervals including increments, semi-diameter  and meridian passage at Greenwich :

Nautical Almanac - Sun ENGB 1


Aries  :  hour tables ( Greenwich hour angle - sideral time ) :

Nautical Almanac - Aries - ENGB3




Stars  :  position tables ( sideral hour angle - S.H.A. and declination ) - 63 stars are tabulated :

Nautical Almanac - stars - ENGB5


On the nautical almanac the astronomical events are shown according to the geographic coordinates : nautical twilights, sunrise and sunset . Time is expressed in Universal Time (U.T.)  - Latitude 50° 24,5'  North and longitude 0°00,1 West are the geographic coordinates (approx.) of the lightvessel "Greenwich" at the southern entrance to The Channel ( in the middle of the separation zone ).  New coordinates are required for the real estimated position (or country, town etc.). :

Nautical Almanac - sunrise sunset ENGB 4
In the sheet " standard latitudes "  events at fixed latitudes/greenwich longitude are shown like a traditional nautical almanac :
nautical almanac - astronomical events at Greenwich

accuracy

Hour angles and declinations are calculated with a precision equal to that given in the traditional Nautical Almanac. VSOP87 Theory has been  incorporated in the program and allows the calculation of the position of the sun with an error not exceeding 2". Results has been rounded to the nearest value (0,1 arcminute).

responsibility

This is a freeware software  (excel spreadsheet) but the redistribution is forbidden and the download is possible from this website only. This Almanac does not intend to substitute the traditional Nautical Almanac. The software has the following characteristic: " as is " without any express or implied warranties of any kind. The user assumes full responsibility for the use of the software.

download of the nautical almanac

The Nautical Almanac  of the stars excel file -   size : 1,42 Mb
Increments and corrections table pdf file   -   size : 535 Kb

Every december the version of the next year will be issued. The file ( for year 2012 ) is availabe in "binary format " ( office 2007 ) too : make a request at roberto@robertoiori.it  

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I'll be happy to receive suggestions or comments

© 2012 robertoiori

Bibliography
Jean Meeus  -  Astronomical Algorithms  -  Willmann-Bell, Inc.-Richmond-Virginia
Jean Meeus  -  Astronomical Formulae for C.  -  Willmann-Bell, Inc.-Richmond-Virginia
Pierre Bretagnon - Jean Louis Simon  -  Planetary Programs and Tables from -4000 to +2800  -   Willmann-Bell, Inc.-Richmond-Virginia
Verlag G. Braun  -  Fifth Fundamental Catalogue (KF5)
uptd 3rd january 2012