Fr.: binaire astrométrique
A binary star in which the presence of an unresolved companion is revealed by small oscillations in the movement of the visible component caused by the gravitational influence of the unseen component.
dorin, dodoyi (#)
General: Characterized by or consisting of two parts or
Binary, from L.L. binarius, from bini "two-by-two," from bis "twice, two times;" cf. Av. biš- "twice," bi- "two," Mod.Pers. do "two," PIE *dwo- "two."
Dorin, from Mid.Pers. dorin "double, pair,"
from do (Av. dva-, Skt. dvi-, Gk. duo,
L. duo, E. two, Der. zwei, Fr. deux)
"two" + rin "time, turn."
hesâb-e dorin, ~ dodoi (#)
Fr.: arithmétique binaire
A system of calculation in which the only numerals used are 0 and 1. All the real numbers are represented in terms of powers of 2.
Fr.: astéroïde binaire
A member of a population of double objects in the main → Asteroid Belt or the → Kuiper Belt which are gravitationally bound together. So far about 200 such binary systems have been identified, while their number is increasing. 243 Ida was the first binary asteroid to be discovered during the Galileo spacecraft flyby in 1993. Other examples are → Antiope and Kalliope in the main belt and QG298 in the Kuiper Belt. The importance of these objects resides in the fact that systems with well measured orbital parameters allow the total mass to be estimated. If the sizes of the components are known then their densities can be accurately calculated. Density is an important parameter since it yields information about composition and internal structure.
binary black hole
siyah câl-e dorin
Fr.: trou noir binaire
binary digit (bit)
raqam-e dorin, ~ dodoi, bit
Fr.: chiffre binaire
Either of the digits 0 or 1, used in the → binary number system.
Fr.: fréquence des binaires
The fraction of stars that have at least one → companion. It is at least 50%. The binary fraction appears to increase with increasing → primary star mass, at least among the more massive stars: the → O stars and → B stars have a companion frequency of at least 70%, while for the → G stars the binary frequency is around 50% and the → M stars may have an even lower binary frequency of around 30-40%. Brown dwarfs are rare as companions to lower-main-sequence stars, although brown-dwarf binaries appear not to be rare. An increase in binary frequency with mass would be expected if most stars form in → multiple systems that disintegrate, since the more massive stars would then preferentially remain in binaries while the less massive ones would preferentially be ejected as single stars (see Richard B. Larson, 2001, in IAU Symposium 200, p. 93 and references therein).
Fr.: galaxie binaire
A pair of galaxies in orbit around each other.
→ binary; → galaxy.
binary number system
râžmân-e adadhâ-ye dirini
Fr.: système des nombres binaires
A → numeral system that has 2 as its base and uses only two digits, 0 and 1. The positional value of each digit in a binary number is twice the place value of the digit of its right side. Each binary digit is known as a bit. The decimal numbers from 0 to 10 are thus in binary 0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, and 1010. And, for example, the binary number 111012 represents the decimal number (1 × 24) + (1 × 23) + (1 × 22) + (0 × 21) + (1 × 20), or 29. In electronics, binary numbers are the flow of information in the form of zeros and ones used by computers. Computers use it to manipulate and store all of their data including numbers, words, videos, graphics, and music.
Fr.: opération binaire
A mathematical operation that combines two numbers, quantities, sets, etc.,
to give a third. For example, multiplication of two numbers is a binary operation.
pulsâr-e dorin, tapâr-e ~
Fr.: pulsar binaire
A pulsar in a → binary system, the companion of which often being a → neutron star or a → white dwarf. The only known binary system with two pulsars components is the → double pulsar. As of 2010 about 70 binary pulsars have been identified. They are ideal laboratories for testing and studying the effects predicted by → general relativity, such as → spin precession, → Shapiro time delay, and → gravitational waves. The prototype, called PSR 1913+16, was discovered in 1974 by Russell A. Hulse and Joseph H. Taylor, Jr., who received the Nobel Prize for Physics in 1993. → Hulse-Taylor pulsar.
Fr.: étoile binaire
→ binary; → star.
binary supermassive black hole
siyah-câl-e abar-porjerm-e dorin
Fr.: trou noir supermassif double
A → dual supermassive black hole whose components are separated by a few parsecs.
Fr.: système binaire
Two astronomical objects revolving around their common center of mass.
→ binary; → system.
Fr.: arbre binaire
birth binary population (BBP)
porineš-e dorinhâ hengâm-e zâdmân
Fr.: population binaire à la naissance
In star formation models, the population of binary components formed via random pairing of stars distributed according to the → canonical IMF.
black hole binary
siyah câl-e dorin
Fr.: trou noir binaire
Of or relating to an object that revolves around a → binary system.
close binary star
setâre-ye dorin-e kip
Fr.: étoile binaire serrée
A binary system in which the separation of the component stars is comparable to their diameters, so that they influence each other's evolution most commonly by the tidal forces.
close binary system
râžmân-e dorin-e kip
Fr.: système binaire serré
A → binary system in which the distance separating the stars is comparable to their size. Most close binaries are spectroscopic binaries (→ spectroscopic binary) and/or eclipsing binaries (→ eclipsing binary). In most of them → mass transfer occurs at some stage, an event which profoundly affects the → stellar evolution of the components. The evolution of close binaries depends on the → initial masses of the two stars and their → separation. When the more massive star evolves into a → red giant first, material will spill through the inner point onto its companion, thereby affecting its companion's evolution. Mass transfer can also alter the separation and → orbital period of the binary star.