optikë aktive

Exactly 365. 25 days, in which a century (100 years) is exactly 36525 days and in which 1900. 0 corresponds exactly to 1900 January 0. 5 (from the Julian-date system, which is ...

heliocentrik

天文学; 普通天文学

Referring to the sun. A heliocentric orbit is one based on the sun as one of the two foci of the (elliptical) orbit (or as the center of a circular orbit); a heliocentric ...

datë juliane

天文学; 普通天文学

The interval of time in days (and fraction of a day) since Greenwich noon on Jan. 1, 4713 BC. The JD is always half a day off from Universal Time, because the current definition ...

ekuinoks

天文学; 普通天文学

Either of the two points (vernal, autumnal) on the celestial sphere where the ecliptic (which is the apparent path of the sun on the sky) intersects the celestial equator. Due to ...

shtrirje

天文学; 普通天文学

Angular distance of a celestial object from the sun in the sky. In standard ephemerides, this is usually denoted by the Greek letter epsilon (or by the abbreviation "Elong. "). A ...

pjerrësi

天文学; 普通天文学

One element of the astronomical coordinate system on the sky that is used by astronomers. Declination, which can be thought of as latitude on the earth projected onto the sky, is ...