Ecliptic

The Sun appears to move with respect to the fixed stars, as seen from the orbiting Earth. The ecliptic is the yearly path the Sun appears to follow on the celestial sphere. This process repeats itself in a cycle lasting a little over 365 days.

The ecliptic is the circular path on the celestial sphere that the Sun appears to follow over the course of a year; it is the basis of the ecliptic coordinate system. The term also refers to the plane of this path, which is coplanar with Earth's orbit around the Sun (and hence the Sun's apparent orbit around Earth).[1] The ecliptic is not normally noticeable from Earth's surface because Earth rotates, carrying the observer through the cycles of sunrise and sunset, which obscure the Sun's apparent motion against the background of fixed stars.

Sun's apparent motion

The motions as described above are simplifications. Due to the movement of Earth around the Earth–Moon center of mass, the apparent path of the Sun wobbles slightly, with a period of about one month. Due to further perturbations by the other planets of the Solar System, the Earth–Moon barycenter wobbles slightly around a mean position in a complex fashion. The ecliptic is actually the apparent path of the Sun throughout the course of a year.[2]

Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward[3] every day. This small difference in the Sun's position against the stars causes any particular spot on Earth's surface to catch up with (and stand directly north or south of) the Sun about four minutes later each day than it would if Earth would not orbit; a day on Earth is therefore 24 hours long rather than the approximately 23-hour 56-minute sidereal day. Again, this is a simplification, based on a hypothetical Earth that orbits at uniform speed around the Sun. The actual speed with which Earth orbits the Sun varies slightly during the year, so the speed with which the Sun seems to move along the ecliptic also varies. For example, the Sun is north of the celestial equator for about 185 days of each year, and south of it for about 180 days.[4] The variation of orbital speed accounts for part of the equation of time.[5]

Other Languages
Afrikaans: Sonnebaan
Alemannisch: Ekliptik
العربية: مسار الشمس
asturianu: Eclíptica
azərbaycanca: Ekliptika
беларуская: Экліптыка
български: Еклиптика
bosanski: Ekliptika
brezhoneg: Ekliptik
català: Eclíptica
čeština: Ekliptika
dansk: Ekliptika
Deutsch: Ekliptik
dolnoserbski: Ekliptika
eesti: Ekliptika
Ελληνικά: Εκλειπτική
español: Eclíptica
Esperanto: Ekliptiko
euskara: Ekliptika
français: Écliptique
Gaeilge: Éiclipteach
galego: Eclíptica
한국어: 황도
Հայերեն: Խավարածիր
हिन्दी: सूर्यपथ
hornjoserbsce: Ekliptika
hrvatski: Ekliptika
Bahasa Indonesia: Ekliptika
íslenska: Sólbaugur
italiano: Eclittica
қазақша: Эклиптика
Kiswahili: Ekliptiki
Кыргызча: Эклиптика
latviešu: Ekliptika
Lëtzebuergesch: Ekliptik
lietuvių: Ekliptika
magyar: Ekliptika
македонски: Еклиптика
مازِرونی: دایرةالبروج
Bahasa Melayu: Ekliptik
日本語: 黄道
norsk nynorsk: Ekliptikken
occitan: Ecliptica
oʻzbekcha/ўзбекча: Ekliptika
ਪੰਜਾਬੀ: ਸੂਰਜੀ ਪੰਧ
polski: Ekliptyka
português: Eclíptica
română: Ecliptică
русский: Эклиптика
саха тыла: Эклиптика
Scots: Ecliptic
Simple English: Ecliptic
slovenčina: Ekliptika
slovenščina: Ekliptika
српски / srpski: Еклиптика
srpskohrvatski / српскохрватски: Ekliptika
suomi: Ekliptika
svenska: Ekliptikan
татарча/tatarça: Эклиптика
Türkçe: Tutulum
українська: Екліптика
Tiếng Việt: Hoàng đạo
吴语: 黃道
粵語: 黃道
中文: 黄道