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

A comet that passes extremely close to the Sun's → surface, in some cases within a few thousand kilometres of the Sun's surface. The Great Comet of 1965, Ikeya-Seki, was a member of the sun-grazer family, coming within about 650,000 km of the Sun's surface. Passing so close to the Sun, sun-grazers are subjected to destructive → tidal forces along with intense solar heat which can completely evaporate them during such a → close approach.

→ Sun; → grazer.

A prefix meaning "not."

M.E., O.E. un- (cf. O.Fris., O.H.G., Ger. un-, Goth. un-, Du. on-), cognate with Pers. nâ-, as below.

Nâ- "not," variants na "no, not," ma- "not" (prohitive); Mid.Pers. nê, ma "no, not;" O.Pers. naiy, nai "not;" Av. nôit, naē "not;" cf. Skt. ná "not;" L. ne-, in-, un-; Gk. ni; Lith. nè; O.C.S. ne "not;" E. un-, as above; PIE *ne-.