Defn: The art of describing or delineating the stars; a description or mapping of the heavens.

ASTROITE
As"tro*ite, n. Etym: [L. astroites: cf. F. astroite.]

Defn: A radiated stone or fossil; star-stone. [Obs.] [Written also astrite and astrion.]

ASTROLABE As"tro*labe, n. Etym: [OE. astrolabie, astrilabe, OF. astrelabe, F. astrolabe, LL. astrolabium, fr. Gr.

1. (Astron.)

Defn: An instrument for observing or showing the positions of the stars. It is now disused.

Note: Among the ancients, it was essentially the armillary sphere. A graduated circle with sights, for taking altitudes at sea, was called an astrolabe in the 18th century. It is now superseded by the quadrant and sextant.

2. A stereographic projection of the sphere on the plane of a great circle, as the equator, or a meridian; a planisphere. Whewell.

ASTROLATER
As*trol"a*ter, n.

Defn: A worshiper of the stars. Morley.