An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

An analysis technique applied to some atomic nuclei that have the property to behave as small magnets and respond to the application of a magnetic field by absorbing or emitting electromagnetic radiation. When nuclei which have a magnetic moment (such as ¹H, ¹³C, ²⁹Si, or ³¹P) are submitted to a constant magnetic field and at the same time to a radio-frequency alternating magnetic field, the nuclear magnetic moment is excited to higher energy states if the alternating field has the specific resonance frequency. This technique is especially used in spectroscopic studies of molecular structure and in particular provides valuable information in medicine that can be used to deduce the structure of organic compounds.

→ nuclear; → magnetic; → resonance.

The situation in which two orbiting objects exert a regular, periodic gravitational influence on each other and therefore their orbital frequencies are related by a ratio of two small → integers. Orbital resonance often results in an unstable interaction in which bodies exchange momentum and shift orbits until the resonance disappears. The resonance increases the eccentricity until a body approaches a planet too closely and the body is slung away.

→ orbital; → resonance.

A → Lindblad resonance expressed by: Ω_p = Ω + κ/m.

→ outer; → Lindblad resonance.

Th desorption of surface substances by ultraviolet radiation.

→ photo-; → desorption.

Of or relating to an epoch earlier than the formation of the Sun.

→ pre-; → solar.

A → refractory → nanoparticle embedded in → meteorites and → interplanetary dust particles whose → isotopic ratios suggest formation earlier than the Solar System.

→ presolar; → grain.

1) The degree to which an → optical system renders visible separate parts of an object. Also known as → angular resolution and → spatial resolution. See also → spectral resolution.
2) The time interval between successive discernible signals. → temporal resolution.

Verbal noun of → resolve.

Finding the → components of a → force which act in specified → directions.

→ resolution; → force.

To separate and make visible the individual parts of an → image or → spectral feature.

M.E. resolven, from L. resolvere "to loosen, undo, settle," from → re- + solvere "to loosen," → solve.

Vâgošudan, from prefix vâ-, → re-, + gošudan, gošâdan "to loose, open up, let free;" gošâd "opened; ample, broad;" Mid.Pers. wišâdan "to let free;" Khotanese hīyā "bound;" O.Pers. višta "untied, loosened," vištāspa- "with loosened horses" (personal name); Av. višta "untied," ā-hišāiiā "holds fettered," hita- "fastened, tied on, put to;" cf. Skt. sā- "to bind, fasten, fetter," sitá- "bound," ví-sita- "untied."

Separated and made visible in an → image or → spectral feature. → resolved line.

Past participle of → resolve.

A → spectral line that is not contaminated by other nearby lines.

→ resolved; → line.

A measure of an optical system's ability to produce an image which separates two points or parallel lines on the object.

Resolving verbal adj. of → resolve; → power.

1) The state of a → mechanical system in which the → amplitude of → oscillation is increased when it is subjected to stimulus from another source at or near its own natural → frequency.
2) The condition of an electrical circuit with respect to a given frequency in which the net reactance is zero and the current flow a maximum.
3) A relationship in which the → orbital period of one body is related to that of another by a simple integer fraction, such as 1/2, 2/3, 3/5. → Laplace resonance, → Lindblad resonance, → resonance orbit .
4) → resonance particle.

Resonance, from M.Fr. resonance, from L. resonantia "echo," from resonare "to resound," from re- "again, back" + sonare "to sound."

Bâzâvâyi, from bâz- "again, back," → re-, + âvâ "voice, sound" (related to âvâz "voice, sound, song," bâng "voice, sound, clamour" (Mid.Pers. vâng), vâžé "word;" Av. vacah- "word," vaocanghê "to decalre" (by means of speech), from vac- "to speak, say;" cf. Skt. vakti "speaks, says," vacas- "word;" Gk. epos "word;" L. vox "voice;" PIE base *wek- "to speak") + -yi noun suffix.

Capture by an atomic nucleus of a particle whose energy is equal to one of the energy levels of the nucleus.

→ resonance; → capture.

The frequency at which a system is in → resonance.

→ resonance; → frequency.

For a particular atom, the spectral line corresponding to the longest wavelength arising from a transition between the ground state and an excited state.

→ resonance; → line.

An orbit which is in → orbital resonance with another orbit.

→ resonance; → orbit.

A hadronic particle which exists for only a very brief time (10^-23 seconds) before decaying into hadrons; also called resonance. The existence of a resonance cannot be observed directly; it can only be inferred from studying the longer-lived products of its decay.

→ resonance; → particle.

A neutron with an energy between 1 eV and 0.01 MeV.

→ resonance; → region; → neutron.

Pertaining to a system in a state of → resonance; producing resonance; resounding.

Verbal adj. from → resonate.