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.
a great circle on the celestial sphere passing through the celestial poles and a specified point, such as a star
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.
[ouuh r-glas, -glahs, ou-er-] /ˈaʊərˌglæs, -ˌglɑs, ˈaʊ ər-/ noun 1. an instrument for measuring time, consisting of two bulbs of joined by a narrow passage through which a quantity of sand or mercury runs in just an . adjective 2. having a notably slim or narrow waist, midsection, or joining segment: She has an hourglass […]
- Hourglass contraction
hourglass contraction hour·glass contraction (our’glās’) n. Constriction of the middle portion of a hollow organ, such as the stomach or the uterus.
- Hourglass murmur
hourglass murmur n. A murmur in which there are two areas of maximum loudness, one preceding and the other following a softer midpoint. Its graph resembles an hourglass.
- Hourglass stomach
hourglass stomach n. A condition in which there is an abnormal constriction of the stomach wall dividing it into two cavities, cardiac and pyloric.