Fr.: puissance solaire
Any power obtained by converting solar radiation into useful power.
Fr.: sonde solaire
A space probe designed to gather data about the Sun.
Fr.: protubérances solaires
A large, arch-shaped filament of hot gas extending outward from the Sun's surface. More at → prominence.
→ solar; → prominence.
Fr.: rayonnement solaire
All the constituents making up the Sun's emission: photons, electrons, protons, neutrinos, and atomic nuclei.
solar radiation pressure
fešâr-e tâbeš xoršid (#)
Fr.: pression du rayonnement solaire
The → radiation pressure of solar photons, which pushes a comet's dust outward to form a → dust tail.
Fr.: rayons solaires
Plural form of → solar radius.
Fr.: rayon solaire
A unit of length, representing the radius of the → Sun, used to express the size of stars in astrophysics. It is equivalent to: 695,700 km, 0.00465047 → astronomical units, 7.35355 × 10-8 → light-years, and 2.32061 → light-seconds.
carxeš-e xoršid (#)
Fr.: rotation du Soleil
The motion of the Sun around an axis which is roughly perpendicular to the plane of the → ecliptic; the Sun's rotational axis is tilted by 7.25° from perpendicular to the ecliptic. It rotates in the → counterclockwise direction (when viewed from the north), the same direction that the planets rotate (and orbit around the Sun). The Sun's rotation is differential, i.e. the period varies with latitude on the Sun (→ differential rotation). Equatorial regions rotate in about 25.6 days. The regions at 60 degrees latitude rotate more slowly, in about 30.9 days.
Fr.: satellite solaire
A space vehicle designed to orbit about the Sun.
binâb-e xoršid (#), ~ xoršidi (#)
Fr.: spectre solaire
The spectrum of the Sun's electromagnetic radiation, consisting of a continuum spectrum marked with dark absorption lines.
Fr.: Système solaire
The collective name for the Sun and all objects gravitationally bound to it. These objects are the eight planets, their 166 known moons, five dwarf planets, and billions of small bodies. The small bodies include asteroids, icy Kuiper belt objects, comets, meteoroids, and interplanetary dust. The solar system is roughly a sphere with a radius greater than 100,000 AU. Planets, satellites, and all interplanetary material together comprise only about 1/750 of the total mass. Geochemical dating methods show that the solar system chemically isolated itself from the rest of the Galaxy (4.7 ± 0.1) × 109 years ago.
solar system abundance
farâvâni-ye râžmân-e xoršidi
Fr.: abondance dans le système solaire
Same as → protosolar abundance.
→ solar system; → abundance.
teleslop-e xoršidi, durbin-e ~
Fr.: télescope solaire
A telescope designed so that heating effects produced by the Sun do not distort the images.
zamân-e xoršidi (#)
Fr.: temps solaire
The time based on the rotation of the Earth relative to the Sun. → mean solar time.
Fr.: tour solaire
A structure used in solar observations in order to raise the equipment above the atmospheric disturbances caused by solar heating of the ground and the radiation of the heat into the atmosphere.
Fr.: jumeau du soleil
An ideal star possessing fundamental physical parameters (mass, chemical composition, age, effective temperature, luminosity, gravity, magnetic fields, equatorial rotation, etc.) very similar, if not identical, to those of the Sun. See also → solar analog; → solar-like star.
→ solar; → twins paradox.
tondâ-ye xoršid, ~ xoršidi
Fr.: vitesse solaire
The rate of change of the Sun's position with respect to the local standard of rest toward the → solar apex.
bâd-e xoršid, ~ xoršidi
Fr.: vent solaire
A mass outflow, consisting of protons, electrons, and other subatomic particles, expelled constantly from the solar corona at about 500 km per second. The solar mass-loss rate in this phenomenon amounts to about 2 x 10-14 solar masses per year, or about 106 tons per second. → stellar wind.
sâl-e xoršidi (#)
Fr.: année solaire
The period of time required for the Earth to make one complete revolution around the Sun. Solar year is a general term for: → tropical year, → vernal equinox year, and → autumnal equinox year, which have different lengths.
Fr.: étoile semblable au soleil
A member of a very broad class of stars in which is found a mixture of late F, early, middle, and, sometimes, late G type dwarfs and sub-giants. See also → solar analog; → solar twin.