Hour circle, in astronomy, a secondary axis in the equatorial coordinate system. The hour circle of a celestial body is the great circle on the celestial sphere that passes through both the body and the north celestial pole. A star's hour circle is used in determining its right ascension and declination.
POPULAR POSTS
-
Standard time, civil time used within a given time zone. The earth is divided into 24 time zones, each of which is about 15° of longitude w...
-
Comet, a small celestial body consisting mostly of dust and gases that moves in an elongated elliptical or nearly parabolic orbit around the...
-
Eclipse, in astronomy, the obscuring of one celestial body by another, particularly that of the sun or a planetary satellite. Two kinds of e...