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

Emission nebulae: The relative amount of a given → chemical element in an ionized nebula with respect to another element, usually → hydrogen. Elemental abundance ratios of → emission nebulae are obtained either by adding the observed → ionic abundances of the element or by using → ionization correction factors. Same as → total abundance.

Elemental, from M.L. elementalis, → element + -al; abundance, from O.Fr. abundance, from L. abundantia "fullness," from abundare "to overflow," from L. ab- "away" + undare "to surge," from unda "water, wave;" → abundance.

1) Being an original or primary source.
2) A basic principle, rule, law, or the like, that serves as the groundwork of a system.

L.L. fundamentalis "of the foundation," from L. fundamentum "foundation," from fundare "to found."

Bonyâdin, adj. of bonyâd "foundation, basis," from *bondâd (Mid.Pers. bune dâtak "foundation, basis"), from bon "basis; root; foundation; bottom" (Mid.Pers. bun "root; foundation; beginning," Av. būna- "base, depth," cf. Skt. bundha-, budhná- "base, bottom," Pali bunda- "root of tree") + dâd "given," from dâdan "to give" (Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," dadāiti "he gives;" Skt. dadáti "he gives," Gk. didomi "I give," tithenai "to put, set, place;" L. dare "to give, offer;" Rus. delat "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do").

A physical constant that cannot be expressed in terms of other constants of nature, such as the charge of the electron.

→ fundamental; → constant.

Same as the → fundamental interaction.

→ fundamental; → force.

The lowest frequency in a complex wave.

→ fundamental; → frequency.

Any of the four interactions in nature between bodies of matter and that are mediated by one or more particles. Also called the → fundamental force. In order of decreasing strength, the four fundamental interactions are the → strong interaction, the → electromagnetic interaction, the → weak interaction, and the → gravitational interaction.

→ fundamental; → interaction.

Same as → elementary particle.

→ fundamental; → particle.

A relatively bright star for which coordinates and proper motion have been determined to a very high degree of accuracy.

→ fundamental; → star.

Of, relating to, or performed by or with one or more instruments.
See also:
→ instrumental broadening, → instrumental flexure, → instrumental magnitude, → instrumental profile, → instrumental response function, → instrumentalism, → instrumentalist.

Adj. of → instrument.

The broadening of a point source caused by the response functions of the telescope and the instrument used.

→ instrumental; → broadening.

An image defect caused by the mechanical flexure of materials; for example the curved-shape image of a long slit in a spectrograph.

→ instrumental; → flexure.

The magnitude derived directly using → Pogson's relation. The instrumental magnitude depends on → detector→ sensitivity, telescope → aperture, exact filter → bandpass, etc. It must be → calibrated to some standard → photometric system.

→ instrumental; → magnitude.

The shape of instrument's response to the input signal. The Fourier transform of the source function by the instrument function.

→ instrumental; → profile.

The mathematical form of the way an instrument affects the input signal.

→ instrumental; → response; → function.

In the philosophy of science, the pragmatic view that a scientific theory is no more than a useful instrument or tool for getting our experiences in some order.

→ instrumental; → -ism.

An astronomer, engineer, or technician who is concerned with the construction of astronomical instruments.

→ instrumental + → -ist.

Of or pertaining to the → mind.

M.E., from M.Fr. mental, from L. mentalis "of the mind," from mens (genitive mentis) "mind," from PIE root *men- "to think."

Menti, mentâl, adjectives of ment, → mind; → -al.

1) Mental capacity or endowment.
2) Mental capacity or endowment (Dictionary.com).

→ mental; → -ity.