List Of Selected Stars For Navigation
Fifty-eight selected navigational stars are given a special status in the field of celestial navigation. Of the approximately 6,000 stars visible to the naked eye under optimal conditions, the selected stars are among the brightest and span thirty-eight constellations of the celestial sphere from the declination of 70° south to 89° north. Many of the selected stars were named in antiquity by the ancient Arabs, Greeks, Romans, and Babylonians.
The star Polaris, often called the "North Star", is treated specially due to its proximity to the north celestial pole. When navigating in the northern hemisphere, special techniques can be used with Polaris to determine latitude or gyrocompass error. The other 57 selected stars have daily positions given in nautical almanacs, aiding the navigator in efficiently performing observations on them. A second group of 115 "tabulated stars" can also be used for celestial navigation, but are often less familiar to the navigator and require extra calculations.
For purposes of identification, the positions of navigational stars — expressed as declination and sidereal hour angle — are often rounded to the nearest degree. In addition to tables, star charts provide an aid to the navigator in identifying the navigational stars, showing constellations, relative positions, and brightness.
Read more about List Of Selected Stars For Navigation: Background, Table, Star Charts, Footnotes
Famous quotes containing the words list of, list, selected and/or stars:
“Religious literature has eminent examples, and if we run over our private list of poets, critics, philanthropists and philosophers, we shall find them infected with this dropsy and elephantiasis, which we ought to have tapped.”
—Ralph Waldo Emerson (18031882)
“Every morning I woke in dread, waiting for the day nurse to go on her rounds and announce from the list of names in her hand whether or not I was for shock treatment, the new and fashionable means of quieting people and of making them realize that orders are to be obeyed and floors are to be polished without anyone protesting and faces are to be made to be fixed into smiles and weeping is a crime.”
—Janet Frame (b. 1924)
“The final flat of the hoes approval stamp
Is reserved for the bed of a few selected seed.”
—Robert Frost (18741963)
“Rather than have it the principal thing in my sons mind, I would gladly have him think that the sun went round the earth, and that the stars were so many spangles set in the bright blue firmament.”
—Thomas Arnold (17951842)