Apparent longitude: Difference between revisions
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'''Apparent longitude''' is [[celestial longitude]] corrected for [[aberration (astronomy)|aberration]] and [[nutation (astronomy)|nutation]] as opposed to ''mean longitude''. |
'''Apparent longitude''' is [[celestial longitude]] corrected for [[aberration (astronomy)|aberration]] and [[nutation (astronomy)|nutation]] as opposed to ''mean longitude''. |
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Apparent longitude is used in the definition of equinox and solstice. At equinox, the apparent geocentric celestial longitude of the Sun is 0° or 180°. At solstice, it is equal to 90° or 270°. This does not match up to declination exactly zero or declination extreme value because the [[celestial latitude]] of the Sun is (less than 1.2 arcseconds but) not zero. |
Apparent longitude is used in the definition of equinox and solstice. At equinox, the apparent geocentric celestial longitude of the Sun is 0{{Orphan|date=November 2010}}° or 180°. At solstice, it is equal to 90° or 270°. This does not match up to declination exactly zero or declination extreme value because the [[celestial latitude]] of the Sun is (less than 1.2 arcseconds but) not zero. |
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== References == |
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{{Reflist}} |
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== Sources == |
== Sources == |
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*{{cite book|title=Astronomical Algorithms|edition=Second|last=Meeus|first=Jean}} |
*{{cite book|title=Astronomical Algorithms|edition=Second|last=Meeus|first=Jean}} |
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{{Portal bar|Astronomy|Stars|Spaceflight|Outer space|Solar System}} |
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[[Category:Celestial coordinate system]] |
[[Category:Celestial coordinate system]] |
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{{Astronomy-stub}} |
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Revision as of 02:25, 4 August 2021
Apparent longitude is celestial longitude corrected for aberration and nutation as opposed to mean longitude.
Apparent longitude is used in the definition of equinox and solstice. At equinox, the apparent geocentric celestial longitude of the Sun is 0
° or 180°. At solstice, it is equal to 90° or 270°. This does not match up to declination exactly zero or declination extreme value because the celestial latitude of the Sun is (less than 1.2 arcseconds but) not zero.
References
Sources
- United States Naval Observatory. Astronomical Almanac Glossary Chapter.
- Meeus, Jean. Astronomical Algorithms (Second ed.).
 | This astronomy-related article is a stub. You can help Wikipedia by expanding it. |