hour circle
noun Astronomy.
a great circle on the celestial sphere passing through the celestial poles and containing a point on the celestial sphere, as a star or the vernal equinox.
Also called
circle of declination.
Origin of hour circle
First recorded in 1665–75
Words nearby hour circle
hounslow,
houphouet-boigny,
houppelande,
hour,
hour angle,
hour circle,
hour hand,
hourglass,
hourglass contraction,
hourglass murmur,
hourglass stomach
British Dictionary definitions for hour circle
hour circle
noun
a great circle on the celestial sphere passing through the celestial poles and a specified point, such as a star
Scientific definitions for hour circle
hour circle
A great circle passing through the poles of the celestial sphere and intersecting the celestial equator at right angles. An hour circle is equivalent to a meridian on Earth and is used in describing the position of a celestial body with respect to an observer's celestial meridian. See more at hour angle.