An Etymological Dictionary of Astronomy and Astrophysics
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The → orbital migration of forming → planets that → accrete enough disk material to exceed the critical mass. This type migrates in a gap created in the → protoplanetary disk. Compare with → Type I migration.

→ type; → migration.

A supernova type whose spectrum contains hydrogen lines. Compared with → Type I supernovae, its → light curve has a broader peak at maximum and dies away more rapidly. The magnitudes are smaller, ranging from M_V = -12 to -13.5, and the ejecta have lower velocities (about 5,000 km/sec). These supernovae, which result from the final evolution of → massive stars, have three main divisions: → Type II-P, → Type II-L, and → Type II-n.

Type II initially introduced by R. Minkowski (1941, PASP 53, 224); → type; → supernova.

The → dust tail of a → comet.

→ type; → tail.

A → Type II supernova which displays a linear decrease in its → light curve.

→ Type II supernova; L short for → linear.

A → Type II supernova which shows intermediate or very narrow width hydrogen → emission lines in the spectra.

→ Type II supernova; n short for → narrow.

A → Type II supernova which reaches a plateau in its → light curve. The vast majority of Type II SNe are characterized by a fast (few days) rise to a flat light curve, most pronounced in the reddest optical bands, with a duration of 80-100 days. This plateau phase is interpreted as the recession of the photosphere as the ejecta expand and cool. The spectra of SNe II-P are typically dominated by strong → P Cygni profiles of hydrogen lines, as well as iron absorption features (for a review, e.g., see Filippenko 1997, ARA&A 35, 309).

→ Type II supernova; P short for → plateau.

Having all or most of the characteristics shared by others of the same kind and therefore suitable as an example of it.

From M.L. typicalis "symbolic," from L.L. typicus "of or pertaining to a type," from Gk. typikos, from typos "impression," from typ(os) + -ikos, → -ic.

Gune-vâr, from guné, → type, + -vâr a suffix meaning "resembling, like" (Mid.Pers. -wâr, Av. -vara, -var, cf. Skt. -vara).