Constella´tion. A number of stars which appear as if situated near each other in the heavens, and are considered as forming a particular division.
Cynosure (sin´o-shōōr or sī´). A name of the constellation Ursa Minor, or the Lesser Bear, which contains, in the tail, the pole star by which mariners are guided.
Declination (dek-lin-a´shun). Distance of any object from the celestial equator, either northward or southward.
Disk. The face or visible projection of a celestial body, usually predicated of the sun, moon, or planets; but the stars have also apparent disks.
Eclipse´. An obscuration or interception of the light of the sun, moon, or other luminous body.
Eclip´tic. The great circle of the heavens which the sun appears to describe in his annual revolution.
Equa´tor. The great circle of the sphere, equally distant from the two poles of the world, or having the same poles as the world.
Equinox (ē´kwi-noks). The precise time when the sun enters one of the equinoctial points, making the day and night of equal length.
Faculae (fa´ku-lē). Certain spots sometimes seen on the sun’s disk, which appear brighter than the rest of his surface.
Fixed Stars. Those which retain the same or very nearly the same position with respect to each other.