An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A spectacular comet that at its closest approach to Earth reached a brightness of -1 magnitude. It was so bright that could be seen even at sunrise. The comet reached → perihelion on 1976 Feb. 25 at 0.20 A.U. and had a fan-shaped tail of dimensions 25° x 25° x 15° on the sky. A few days after perihelion, the nucleus split in four fragments. The → carbon monoxide (CO) molecule in comets was first detected in West. The comet's orbit has a period of about 500,000 years. Formerly designated 1976 VI.

After the Danish astronomer Richard M. West (1941-), who worked at the → European Southern Observatory (ESO); → comet.

The Greatest → elongation of an inferior planet occurring before sunrise.

Superlative of → great; → western; → elongation.

The direction 90° to the left or 270° to the right of → north.

M.E., O.E. "west" "in or toward the west;" cf. O.N. vestr, O.Fris., M.Du., Du. west, Ger. West; PIE base *wes- (Gk. hesperos, L. vesper "evening, west").

Bâxtar "west;" Mid.Pers. apâxtar "north;" Av. apāxtar "northern."

Lying toward or situated in the west. → greatest western elongation.

Adjective from → west.

The position of a planet when it is visible in the eastern sky before dawn.

→ western; → elongation.