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» Online Classroom   »   » Public Discussion of Cel Nav   » Greek letter star names

   
Author Topic: Greek letter star names
annabell


 - posted March 17, 2004 12:40 PM            Edit/Delete Post 
What do the Greek letter alphabet mean next ro star names in the almanac?
David Burch


 - posted March 18, 2004 08:27 AM      Profile for David Burch           Edit/Delete Post 
In the back of the nautical almanac there is a list of another 120 or so stars, in addition to those 57 that appear on each of the daily pages. The data (dec and SHA) are given only monthly in the back of the book, with first 6 mo on the left side and 2nd 6 mo on the right.

The data are sorted by SHA. On one side of the page they call the star by its proper name, such as Capella, and on the right side they refer to the same star with its "Greek letter name" in this case, alpha Aurigae, meaning the "alpha star" of the constellation Auriga.

[This convention of listing the same star with two different names can be confusing, if one does not know ahead of time what is going on.]

This is simply another type of nomenclature for stars, whereby each star in the constellation is ranked according to prominence... or if none is more prominent than others, they simply go in some order through the group (alpha, beta, gamma, delta, episolon, and so on), as in the Big Dipper.

All stars of magnitude 2 or brighter have a proper name, such as Capella, but fainter stars may not have a proper name or if it does the almanac does not use it. These stars, however, all have this Greek letter nommenclature, and they would appear on both sides of the page with that Greek letter name.

You can read more about star nomenclature as it applies to cel nav in The Star Finder Book, or if you want to know all about star names there is the great victorian reference book Star Names, Their Lore and meaning.

--david

From: Starpath, Seattle, WA


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