Definition of Hour angle
1. Noun. The angular distance along the celestial equator from the observer's meridian to the hour circle of a given celestial body.
2. Noun. (astronomy) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day.
Hour Angle Pictures
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Lexicographical Neighbors of Hour Angle
hour angle (current term)
Literary usage of Hour angle
Below you will find example usage of this term as found in modern and/or classical literature:
1. A Manual of Spherical and Practical Astronomy: Embracing the General by William Chauvenet (1900)
"... declination and hour angle (d', t') to the celestial declination and hour angle (d, r). — Let PZ Fi 53 be the true meridian, P the celestial pole, ..."
2. Navigation and Nautical Astronomy: The Practical Part, Containing Rules for by H. W. Jeans (1853)
"When the heavenly body is east of meridian, take the hour angle out of the ... If the heavenly body observed is the sun, the hour angle taken out will also ..."
3. Bulletin by United States Weather Bureau (1902)
"THE MOTION IN hour angle. This was secured as follows: The essential features are ... The apparatus for the movement in hour angle. on Chart 5, or Chart 6. ..."
4. Bulletin of the American Mathematical Society by American Mathematical Society (1919)
"Locate the position M of the observed celestial body by means of its declination 90° — PM and its hour angle MPZ. In the triangle PMZ we have two sides and ..."
5. Determinations of Stellar Parallax by Henry Norris Russell (1911)
"Hour-angle Error and its Elimination. Of the various systematic errors which ... One cause of this may be optical distortion varying with the hour-angle, ..."
6. Proceedings of the Royal Society of London by Royal Society (Great Britain) (1871)
"(3) Using the interpolated hour-angle, azimuth, and altitude found by clause (2), ... I find that all the cases (as azimuth and hour-angle both acute, ..."
7. The Geographical Journal by Royal Geographical Society (Great Britain). (1901)
"So Cancer XVIII. was set to altitude circle 38°, and with the ruler the hour angle of the sun, ie local (apparent) time, at once read off as 81' 10"' am, ..."
8. Astronomy by Simon Newcomb, Edward Singleton Holden (1883)
"The hour-angle of a star is the angular distance between the celestial ... The hour-angle is counted from the meridian towards the west from 0° to 360°, ..."