Fr.: primaire, principal
M.E., from L. primarius "of the first rank, principal," from primus "first."
Naxostân, from naxost, from Mid.Pers. naxust "the first," Parthian Mid.Pers. nxwšt, from naxu, Manichean Parthian nwx "beginning" + -ist superlative suffix, Av. -išta-, cf. Skt. -istha-, Gk. -istos, O.H.G. -isto, -osto, O.E. -st, -est, -ost.
Fr.: corps principal
The body that is being orbited; such as the Sun in the solar system. As regards multiple star systems, the most massive star. → secondary body.
primary cosmic rays
partowhâ-ye keyhâni-ye noxostân
Fr.: rayons cosmiques primaires
High energy charged particles that arrive at Earth's upper atmosphere from outer space. Primary cosmic rays generally do not make it through the atmosphere to reach at the Earth's surface, in contrast to → secondary cosmic rays.
Fr.: éclipse primaire
Of a transiting → exoplanet, the event and the interval of time during which the planet passes in front of its host star. The planet occults a portion of the stellar disk, and a fraction of light from the star is seen after traversal through the atmosphere around the planet's limb. → secondary eclipse.
Fr.: miroir primaire
Fr.: arc-en-ciel primaire
The main rainbow that forms between about 40° and 42° from the
→ antisolar point
(or about 50° from the → antisolar point),
as viewed by the observer. The light path involves
→ refraction and a → single
→ reflection inside the water
→ droplet. If the drops are large, 1
millimeter or more in diameter, red, green, and violet are bright but
there is little blue.