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

A model of radiative transfer that ignores forward scattering of photons; assuming forward-scattered light as un-scattered.

→ quasi-; → single; → scattering; → approximation.

Only one in number; one only; unique; sole.

M.E., from O.Fr. sengle "being one, separate," from L. singulus "one, individual, separate," from sim- (stem of simplus) + diminutive suffix, → -ule.

Tak"single, alone," related to tâq "odd, single," tâ, tâh "piece, part; fold, plait, ply;" Mid.Pers. tak "single," tâg, tâk, tâi "unit, piece."

A type of scattering where photons are scattered only once. Single scattering dominates in → optically thin media, since photons have a high probability of exiting the medium (e.g., a thin cloud) before being scattered again.

→ single; → scattering.

A radio astronomical observation which uses only one antenna, in contrast to interferometric observations.

→ single; → dish; → observation.

A → spectroscopic binary in which only one set of → spectral lines is detectable. The binary nature of the system is deduced from the fact that the spectral lines exhibit periodic → Doppler shifts due to orbital motions in the system. Same as → SB1 binary. See also: → double-lined binary.

→ single; → line; → binary.

A single unit; an unpaired or separate item. → doublet; → octet; → quadruplet.

From → single + -et diminutive suffix, M.E. from O.F. -et (masc.), -ette (fem.).

Taktâyé, literally "single-folded," from tak, → single, + -tâyé, from tâ- "fold, plait, ply; piece, part;" Mid.Pers. tâg "piece, part" + -yé nuance suffix.

In atomic physics, the electronic state of an atom or molecule for which the total → spin angular momentum is zero.

→ singlet; → state.