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

A phenomenon consisting of luminous colorful arcs, rays, and streamers that appear in the Earth's upper atmosphere during the night with the greatest frequency in the northern and southern polar magnetic zones. This → non-thermal radiation is caused by the emission of light from atoms excited by electrons accelerated along the planet's magnetic field lines at the magnetic poles. Fluorescent emission from atomic oxygen at 5557 Å results in a greenish glow, and there is a weaker effect from the red line at 6300 Å. Blue and purple colors are emitted by atomic and molecular nitrogen.

L. Aurora, the Roman goddess of dawn, akin to Av. uš-, ušah- "dawn," Skt. usas-, usah- "dawn," Gk. eos "dawn," Lith. ausra "dawn," O.E. east "east," PIE *ausus- "dawn," from *aus- "to shine."

Ušé, from Av. uš-, ušah-, as above.

The aurora in the Southern hemisphere, also called as Southern Lights.

→ aurora; → south.

The aurora in the Northern hemisphere, also called as Northern Lights.

→ aurora; → north.

Pertaining to the → aurora phenomenon.

→ aurora; → -al.

The → electromagnetic radiation emitted in planetary atmospheres involving the → aurora phenomenon.

→ auroral; → emission.

1) A prominent → forbidden line in the spectra of the aurora at wavelengths of 5577 and 6300 Å giving the aurora its characteristic green and red colors. Both are emitted by atomic oxygen, the former in its transition from the second lowest excited electronic state (¹S) to the lowest excited electronic state (¹D), the latter in its transition from the lowest excited electronic state (¹D) to the atomic ground state (³P).
2) A forbidden line emitted by interstellar ionized gas by several atomic species (O, O⁺, O⁺⁺, N⁺, S⁺⁺, etc.) corresponding to the transition from the state ¹S to ¹D. → forbidden line; → nebular line; → transauroral line.

→ auroral; → line.

A roughly circular band around either geomagnetic pole above which there is a maximum of auroral activity. It lies about 10 to 15° of geomagnetic latitude from the geomagnetic poles.

→ auroral; → zone.

1) To establish as genuine.
2) To prove beyond doubt the authorship or origin of (e.g. to authenticate a painting). → authentication.

From L.L. authenticus, from Gk. authentikos "original, primary, at first hand," from authent(es) "one who does things himself," from aut-, from autos "self, one's own," of unknown origin, + -hentes "doer" + -ikos, → ics.

Râstin "genuine, authentic," from râst "right, true; just, straight" (Mid.Pers. râst "true, straight, direct;" O.Pers. rāsta- "straight, true," rās- "to be right, straight, true;" Av. rāz- "to direct, put in line, set," razan- "order;" cf. Skt. raj- "to direct, stretch," rjuyant- "walking straight;" Gk. orektos "stretched out;" L. regere "to lead straight, guide, rule," p.p. rectus "right, straight;" Ger. recht; E. right; PIE base *reg- "move in a straight line," hence, "to direct, rule") + -in adj. suffix.
Šomârdan "to consider; to reckon, count, compute;" Mid.Pers. ôšmârtan, ôšmurtan "to reckon, calculate, enumerate, account for," from Av. base (š)mar- "to have in mind, remember, recall," pati-šmar- "to recall; to long for," hišmar-, cf. Skt. smar- "to remember, become aware," smarati "he remembers," L. memor, memoria, Gk. mermera "care," merimna "anxious thought, sorrow," martyr "witness."

Computers: The process by which a user's identity is checked within the network to ensure that the user has access to the requested resources.

Verbal noun of → authenticate.

1) The writer of a book, article, or other text. One who practices writing as a profession.
2) An originator or creator, as of a theory or plan.
3) Author God.

M.E. auctour, from O.Fr. autor, from L. auctor, "creator, enlarger, founder, master, leader," literally "one who causes to grow," from auctus, p.p. of augere "to increase," from PIE root aug- "to increase".

Dâtâr, from Mid.Pers. dâtâr/dâdâr "creator," from Av. and O.Pers. dâtâr "creator," from dâ- "to create, make, appoint," Skt. dhatr "author, creator, preserver, bearer." The Mod.Pers. form of this word in classical literary works is dâdâr, used mainly as noun or adjective for "God, the creator."

Of, relating to, or characterized by strict obedience to authority.

From authorit(y), → authority, + suffix -arian.

1) The enforcement or advocacy of strict obedience to authority at the expense of personal freedom.
2) Lack of concern for the wishes or opinions of others (OxfordDictionaries.com).

→ authoritarian; → -ism.

1) Recognized or accepted as being true or reliable.
2) Exercising or asserting authority; commanding.
3) Possessing or supported by authority; official (Dictionary.com).

From authorit(y), → authority, + suffix -ative.

1) The power to determine, adjudicate, or otherwise settle issues or disputes; jurisdiction; the right to control, command, or determine (Dictionary.com).
2) A person or body of persons in whom authority is vested, as a governmental agency (Dictionary.com).

→ author; → -ity.

Dâtârgân, from dâtâr, → author, + -gân, on the model of xodâygân "a great lord."

1) The act, fact, or occupation of writing.
2) Source or origin, as of a book or idea.

→ author.

Gk., from autos "self, one's own," of unknown origin.

Xod-, from xod "self," Av. hva- "self, own."

1) In radio astronomy, a process performed by an → autocorrelator.
2) In statistics, a linear relation between values of a random variable over time.
3) In electronics, a technique used to detect cyclic activity in a complex signal.

Autocorrelation, from → auto- "self" + → correlation.

Xod-hambâzâneš, from xod- "self" + hambâzâneš, → correlation.

A mathematical function that describes the correlation between two values of the same variable at different points in time.

→ autocorrelation; → function.

In radio astronomy, a spectrograph which correlates the signal with itself with various time delays, and extracts the frequency spectrum of the signal. → correlator.

Autocorrelator, agent n. from → autocorrelate + → -or.

Xod-hambâzângar, agent n. from xod-, → auto-, + hambâzângar, → correlator.

The → covariance of a → time series overt time.

→ auto-; → covariance.