An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < ali ele mag mag mag mag mag > >>

Number of Results: 139 Search : magnet
  آهنربا، مغناتیس   
âhanrobâ (#), meqnâtis (#)

Fr.: aimant   

An object that produces a magnetic field around itself.

From L. magnetum (nom. magnes) "lodestone," from Gk. ho Magnes lithos "the Magnesian stone," from Magnesia region in Thessaly where magnetized ore was obtained.

Âhanrobâ, literally "iron attracting, iron robbing," from âhaniron + robâ agent noun of robudan, robâyidan "to attract, to grab, rob;" Av. urūpaiieinti "to cause racking pain(?);" cf. Skt. rop- "to suffer from abdominal pain," rurupas "to cause violent pain," ropaná- "causing racking pain," rópi- "racking pain;" L. rumpere "to break;" O.E. reofan "to break, tear."
Meqnâtis, from Ar., from Gk., as above.

magnetâr (#)

Fr.: magnétar   

A highly magnetized → neutron star with fields a thousand times stronger than those of → radio pulsars. There are two sub-classes of magnetars, → anomalous X-Ray pulsar (AXP)s and → soft gamma repeater (SGR)s, that were thought for many years to be separate and unrelated objects. In fact SGRs and AXPs are both neutron stars possessing → magnetic fields of unprecedented strength of 1014 - 1016 G, and that show both steady X-ray pulsations as well as soft gamma-ray bursts. Their inferred steady X-ray luminosities are about one hundred times higher than their → spin-down luminosities, requiring a source of power well beyond the magnetic dipole spin-down that powers → rotation-powered pulsar (RPP)s. New high-energy components discovered in the spectra of a number of AXPs and SGRs require non-thermal particle acceleration and look very similar to high-energy spectral components of young rotation-powered pulsars (A. K. Harding, 2013, Front. Phys. 8, 679).

From magnet, contraction of → magnetic + -(s)tar, from → star.

  مغناتیسی، مغناتی، آهنرباییک   
meqnâtisi (#), meqnâti, âhanrobâyik

Fr.: magnétique   

Of or pertaining to a magnet or magnetism.

From → magnet + → -ic.

Meqnâtisi, meqnâti, from meqnâtis, → magnet; âhanrobâyik, from âhanrobâ, → magnet, + → -ik, → -ic.

magnetic advection
  پهنبز ِ مغناتیسی   
pahnbaz-e meqnâtisi

Fr.: advection magnétique   

The transport of the magnetic field by a fluid. It is given by the term ∇ x (v x B) in the → induction equation.

magnetic; → advection.

magnetic axis
  آسه‌ی ِ مغناتیسی   
âse-ye meqnâtisi

Fr.: axe magnétique   

The imaginary straight line joining the two → poles of a → magnet.

magnetic; → meridian.

magnetic bottle
  بطری ِ مغناتیسی   
botri-ye meqnâtisi (#)

Fr.: bouteille magnétique   

Any configuration of → magnetic fields used in the containment of a → plasma during controlled → thermonuclear reaction experiments.

magnetic; → bottle.

magnetic braking
  لگامش ِ مغناتیسی   
legâmeš-e meqnâtisi

Fr.: freinage magnétique   

The process whereby a star which loses mass slows down under the action of its → magnetic field. The stellar material follows the → magnetic field lines extending well beyond the stellar surface. The material gain → angular momentum and the underlying object is slowed down. Magnetic braking is an efficient mechanism for removing angular momentum from the the rotating object. See also → disk locking.

magnetic; → braking.

magnetic bremsstrahlung
  لگام-تابش ِ مغناتیسی   
legâm-tâbeš-e meqâtisi

Fr.: rayonnement de freinage magnétique   

Same as → synchrotron radiation.

magnetic; → bremsstrahlung.

magnetic buoyancy
  بالارانی ِ مغناتیسی   
bâlârâni-ye meqnâtisi

Fr.: flottabilité magnétique   

The phenomenon whereby the presence of a → magnetic field can make a portion of → compressible fluid less dense than its surroundings, so that it floats upward under the influence of gravity. This magnetic buoyancy is thought, in fact, to be the mechanism by which magnetic flux tubes rise through the Sun's → convection zone and break at the surface in the form of → sunspots. The Sun's rotation would have a major effect on the rate at which these magnetic flux tubes rise. The rotation substantially lengthen the time taken for the flux tubes to reach the surface (D. J. Acheson, 1979, Nature 277, 41).

magnetic; → buoyancy.

magnetic cataclysmic binary
  دورین ِ گتلوری ِ مغناتیسی   
dorin-e gatluri-ye meqnâtisi

Fr.: binaire cataclysmique magnétique   

A cataclysmic binary in which the white dwarf primary has a strong magnetic field that radically affects the accretion flow in the system. → polar

magnetic; → cataclysmic; → binary.

magnetic cloud
  ابر ِ مغناتیسی   
abr-e meqnâtisi

Fr.: nuage magnétique   

A transient ejection in the → solar wind having an enhanced field, a large and smooth change in field direction, and a low → proton temperature compared to the ambient proton temperature (L. F. Burlaga, 1995, Interplanetary Magnetohydrodynamics, Oxford Univ. Press, 89-114).

magnetic; → cloud.

magnetic compass
qotbnemâ (#)

Fr.: compas magnétique   


magnetic; → compass.

magnetic connectivity
  هابندندگی ِ مغناتیسی   
hâbandandegi-ye meqnâtisi

Fr.: connectivité magnétique   

Of magnetic field lines, the condition for them to be connected or the process whereby they become connected or connective.

magnetic;→ connectivity.

magnetic constant
  پایای ِ مغناتیسی   
pâyâ-ye meqnâtisi (#)

Fr.: constante magnétique   

A physical constant relating mechanical and electromagnetic units of measurement. It has the value of 4π × 10-7 henry per meter. Also called the permeability of free space, or → absolute permeability.

magnetic; → constant.

magnetic convection
  همبز ِ مغناتیسی   
hambaz-e meqnâtisi

Fr.: convection magnétique   

Thermal → convection modified by the presence of magnetic fields.

magnetic; → convection.

magnetic declination
  واکیلش ِ مغناتیسی   
vâkileš-e meqnâtisi

Fr.: déclinaison magnétique   

In terrestrial magnetism, the difference between → true north (the axis around which the earth rotates) and magnetic north (the direction the needle of a compass will point,→ magnetic pole).

magnetic; → declination.

magnetic diffusion
  پخش ِ مغناتیسی   
paxš-e meqnâtisi

Fr.: diffusion magnétique   

The process whereby the magnetic field tends to diffuse across the plasma and to smooth out any local inhomogeneities under the influence of a finite resistance in the plasma. For a stationary plasma the → induction equation becomes a pure → diffusion equation: ∂B/∂t = Dm2B, where Dm = (μ0σ0)-1 is the → magnetic diffusivity.

magnetic; → diffusion.

magnetic diffusivity
  پخشندگی ِ مغناتیسی   
paxšandegi-ye meqnâtisi

Fr.: diffusivité magnétique   

The → diffusion coefficient for a magnetic field. It is expressed as: η = 1/(μ0σ), where μ0 is the → magnetic permeability and σ the → conductivity.

magnetic; → diffusivity.

magnetic dip
  نشیب ِ مغناتیسی   
našib-e meqnâtisi

Fr.: inclinaison magnétique   

In terrestrial magnetism, the angle that a → magnetic needle makes with the horizontal plane at any specific location. The angle of magnetic dip at the → magnetic poles of Earth is 90°. Also called → inclination and → dip.

magnetic; → dip.

magnetic dipole
  دوقطبه‌ی ِ مغناتیسی   
doqotbe-ye maqnâtisi

Fr.: dipole magnétique   

A system that generates a → magnetic field in which the field is considered to result from two opposite poles, as in the north and south poles of a magnet, much as an → electric field originates from a positive and a negative charge in an → electric dipole. A loop carrying an electric current also acts as a magnetic dipole. Magnetic dipoles experience a torque in the presence of magnetic fields. → dipole moment; → magnetic moment.

magnetic; → dipole.

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