# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 81 Search : number
 Abbe number   عدد ِ آبه   adad-e AbbeFr.: nombre d'Abbe   The reciprocal of the → dispersive power of a substance. Also known as constringence. aberrational day number   شماره‌ی ِ روز ِ بیراهشی   šomâre-ye ruz-e birâhešiFr.: nombre de jours d'aberration   A → Besselian day number denoted by C or D.→ aberration; → -al; → day; → number. Alfvén Mach number   عدد ِ ماخ ِ آلفونی   adad-e Mach-e AlfvéniFr.: nombre de Mach alfvénique   The ratio of the flow velocity to the → Alfvén speed in a medium.→ Alfvén wave; → number. Alfven Mach number   عدد ِ ماخ ِ آلفونی   adad-e Mach-e AlfvéniFr.: nombre de Mach alfvénique   The ratio of the flow velocity to the → Alfvén speed in a medium.→ Alfvén wave; → number. algebraic number   عدد ِ جبری   adad-e jabri (#)Fr.: nombre algébrique   A number, → real or → complex, that is a → root of a → non-zero polynomial equation whose → coefficients are all → rational. For example, the root x of the polynomial x2 - 2x + 1 = 0 is an algebraic number, because the polynomial is non-zero and the coefficients are rational numbers. The imaginary number i is algebraic, because it is the solution to x2 + 1 = 0.→ algebraic; → number. atomic mass number (A-number)   عدد ِ جرم ِ اتمی   adad-e jerm-e atomi (#)Fr.: nombre de masse atomique   The total number of → protons and → neutrons in the → nucleus of an → atom (symbol A). For example, Oxygen-16 has a mass number of sixteen, because it has eight protons and eight neutrons.→ atomic; → mass; → number. atomic number   عدد ِ اتمی   adad-e atomi (#)Fr.: nombre atomique   The number of → protons in an → atomic nucleus (symbol Z). Same as → Z-number. The atomic number is written as a subscript to the left of the → chemical element name. For example, the most common isotope of oxygen is shown as 816O, which has 8 → protons and its → mass number (A) is 16.→ atomic; → number. Avogadro's number   عدد ِ آووگادرو   adad-e Avogâdro (#)Fr.: nombre d'Avogadro   Named after Amedeo Avogadro (1776-1856), whose law allowed other physicists to calculate Avogadro's number; → constant. azimuthal quantum number   عدد ِ کو‌آنتومی ِ سوگانی   adad-e kuântomi-ye sugâniFr.: nombre quantique azimutal   In quantum mechanics, a quantum number that distinguishes the different shapes of the orbitals.Azimuthal, adj. from → azimuth; → quantum number. baryon number   عدد ِ باریونی   adad-e bâriyoni (#)Fr.: nombre baryonique   1) The difference between the total number of → baryons and the total number of → antibaryons in a system of → subatomic particles. It is a measure of → baryon asymmetry and is defined by the quantity η = (nb - nb-)/nγ, called the → baryon-photon ratio, where nb is the → comoving number density of baryons, nb- is the number of antibaryons, and nγ is that of photons. The value of η for the → cosmic microwave background radiation (CMBR) has been very well determined by the → WMAP satellite to be η = (6.14 ± 0.25) x 10-10. The baryon number is assumed to be constant. The photons created in stars amount to only a small fraction, less than 1%, of those in the CMBR. 2) A property of an → elementary particle represented by a → quantum number. It is equal to +1 for a baryon and -1 for an antibaryon. → Bosons, → leptons, and → mesons have a baryon number B = 0. → Quarks and → antiquarks have baryon numbers of B = +1/3 and -1/3, respectively. The baryon number is → conserved in all observed types of particle-particle interaction.→ baryon; → number. Besselian day number   شماره‌ی ِ روز ِ بسلی   šomâre-ye ruz-e BesseliFr.:   Any of the five quantities denoted by A, B, C, D, and E used in conjunction with → Besselian star constants for the reduction of a star's → mean catalog place to its → apparent place.→ Besselian; → day; → number. binary number system   راژمان ِ عددهای ِ درینی   râžmân-e adadhâ-ye diriniFr.: 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.→ binary; → number; → system. cardinal number   عدد ِ اگرا   adad-e agrâFr.: nombre cardinal   An ordinary number such as 0, 1, 2, or 3, as opposed to an → ordinal number such as 1st, 2nd, or 3rd. Cardinal numbers can be → zero or → positive and are used for counting the things that are assumed to be not divisible.→ cardinal; → number. complex number   عدد ِ همتافت   adad-e hamtâft (#)Fr.: nombre complexe   Any number of the form u = a + bi, where a and b are → real numbers and i imaginary, i.e. i2 = -1.→ complex; → number. composite number   عدد ِ همنهاده   adad-e hamnehâdéFr.: nombre composite   A whole number which is the product of whole numbers other than itself and 1. The opposite of prime number. → compound number.→ composite; → number. compound number   عدد ِ همنات   adad-e hamnâtFr.: nombre composé   A quantity expressed as the sum of two or more quantities of differing units. For example 5 hours and 15 minutes or 4 meters and 20 centimeters. → composite number.→ compound; → number. congruent number   عدد ِ دمساز   adad-e damsâzFr.: nombre congru   Number theory: An → integer N if there exists a → right triangle with → rational sides so that the area of the triangle is N. For example, the number N = 6, because of the 3-4-5 triangle.→ congruent; → number. conjugate complex number   عدد ِ همتافت ِ همیوغ   adad-e hamtâft hamyuq (#)Fr.: nombre complexe conjugé   The conjugate of a → complex number, expressed by ū = a - bi. The complex number and its conjugate have the same real part. Same as → complex conjugate.→ conjugate; → complex; → number. coordination number   شمار ِ هم‌آرایش   šomêr-e hamârâyešFr.: nombre de coordination   1) Crystallography: The number of nearest neighbors of an atom or ion in a → crystal lattice. A large coordination number indicates that the structure is more closely packed. 2) Chemistry: The number of atoms, ions, or molecules surrounding a central atom or ion in a complex.→ coordination; → number. data number (DN)   شمار ِ داده‌ها   šomâr-e dâdehâFr.:   Unit of the analog-to-digital conversion system of a CCD apparatus. For example a 16 bit system may use a maximum of 65536 DN. The acronym ADU, for analog-to-digital unit, is also used.→ data; → number.

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