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

To state or assert positively; maintain as true.

M.E. affermen, affirmen "to decide upon; to state positively," from O.Fr. afermer "affirm, confirm; strengthen," from L. affirmare "to make steady, strengthen," from → ad- "to" + firmare "strengthen, make firm," from firmus, → firm.

Baedešidan, from bar- "upon, to," + deš, → firm, + infinitive suffix -idan.

The act of affirming or something affirmed.

Verbal noun of → affirm.

A linguistic element added to a word or root to produce a derived or inflected form. General term for → infix, → prefix, → suffix, and → circumfix.

From L. affixus "fastened to," p.p. of affigere "fasten to, attach," from af-, variant of → ad- "to" + figere "fasten."

Vand, variant band "tie, band," present stem of Mod.-Mid./Pers. bastan/vastan "to bind, shut;" Av./O.Pers. band- "to bind, fetter," banda- "band, tie;" cf. Skt. bandh- "to bind, tie, fasten;" PIE *bhendh- "to bind," cf. Ger. binden, E. bind.

Describing a lens or optical system with a convergent power of zero, whose object and image points stretch to infinity. Thus, → afocal system.

Afocal, from → a- + → focal.

Akânun, from a- negation prefix, → a- + kânun, → focus. Bikânun, from bi- negation prefix + kânun, → focus.

An optical system with object and image points at infinity.

→ afocal; → system.

1) Behind in place or position; following behind.
2) Later in time than; in succession to; at the close of (Dictionary.com).

M.E., from O.E. æfter "after, next, following in time," from O.E. of "off," cf. apo- + -ter a comparative suffix.

Pas "after," → back-; pasân with place/time suffix -ân.

1) A broad glowing arc of radiance, sometimes seen high in the western sky at → twilight, caused by the → scattering effect of → fine dust particles suspended in the → upper atmosphere.
2) Lingering → radiation that remains after a violent → event such as a → gamma-ray burst. The afterglow of any gamma-ray burst is caused by an event different from the original explosion, likely by → shock waves colliding with the ambient medium. Afterglows occur in a large range of → electromagnetic  → wavelengths.

→ after; → glow.

The part of day from → noon to → evening.

→ after; → noon.

At a later or subsequent time; subsequently.

→ after; → -ward.

A → Luminous Blue Variable star in the constellation → Carina; also known as HD 94910. AG Carinae lies about 6 kpc (20,000 → light-years) away and is surrounded by a → nebula. It is also a → spectroscopic variable, with the variability on time-scale of years. During the epochs of minimum in the visual → light curve (m_V ~ 8.1), the star is relatively hot and has a → WN11 spectral type, showing strong He I, H I, and N II → emission lines, weak He II 4686 Å emission, and Si IV 4088-4116 Å absorption. During the maximum epochs of the light curve (m_V ~ 6.0), the star is cooler, and the spectrum is reminiscent of extreme A-type → hypergiants, with a strong emission of H I, Fe II, and T III lines. The transition between both phases is characterized by the appearance of peculiar features in the spectrum, such as absorption-line splitting, strong → electron-scattering wings in He I and Fe II lines, and apparent → inverse P Cygni profiles in He I lines. The presence of a massive → bipolar nebula around AG Car testifies to a recent (t< 10⁴ years) phase of high → mass loss. The morphology and kinematics of the nebula suggest a → dynamical age of 8.5 × 10³ years and a high mass of → ionized nebular material (~ 4.2 Msun), which is likely composed of → ejecta from the central star. The nebular abundances show evidence of moderate nitrogen → enrichment. Properties of the → circumstellar nebula, studied in the → mid-infrared and → far-infrared, reveal an incredibly high dust mass of ~ 0.25 Msun, → dust temperature between 76 and 99 K, and the presence of large → dust grains of ~ 1 μm, as deduced from far-→ infrared excess. Assuming a normal → gas-to-dust ratio of 100, the total nebular mass of AG Car could be as high as ~ 30 Msun which would be of the order of, or even higher than, the mass of the → Homunculus nebula around → Eta Carinae. At the time when the AG Car nebula was ejected, the → interstellar bubble around the central star likely contained a negligible amount of material compared to the total mass of the nebula, implying that most of the nebular mass was ejected by the central star (Groh et al., 2009, ApJ 698, 1698).

AG, as used in the → variable star designation system; → Carina.

Once more; a second time; in return.

M.E., from O.E. ongean "toward, opposite, against," from on "on" + -gegn "against, toward."

Dobâré, from do, → two, + bâr "time, fold," → twice.

In opposition to; contrary to; adverse or hostile to.

M.E. agens, ageynes, from ageyn, ongean "again," from on + gegn "against, toward," → gegenschein.

Patâr from Mid.Pers. paitiyârak, "every thing that counteracts and checks the good powers: adversaries of the evil powers;" Av. paiti-ār- "to advance against," paiti-ārəna- "adversary," from paiti- "against," → counter-, + ar- "to move," → access; cf. Mod.Pers. patyâré "affliction, misery, misfortune; anything ugly, terrific;" Mid.Pers. padirag, patirak "against, counter-," Sogd. patrêt "against, opposite, toward."

In evolutionary models of → low-mass and → intermediate-mass stars, the occurrence of a → helium shell flash just at the moment when the star is leaving the → asymptotic giant branch phase.

→ AGB; → final; → thermal; → pulse.

1) The length of time that a celestial body or an evolutionary stage of it has existed, i.e. the age of a massive star, the age of a galaxy, a stellar cluster, and so on.
2) a: A period of time in the history of the Universe marked by a distinctive characteristic. → cosmic dark age. b: A division of geologic time in the history of the Earth, usually shorter than an epoch.

From O.Fr. aage, from Vulgar L. *ætaticum, from L. ætatem "period of life," from ævum "lifetime, eternity, age;" cf. Mid.Pers. awâm, âwâm "time, season," Av. âyav- "duration, period, time of life," Skt. âyuh- "life, health". All from PIE *aiw-, *ayu- "vital force, life, long life, eternity."

Senn from Ar. senn "age, lifetime". Asr from Ar.

Same as → Moon's age.

→ Moon's age.

The time elapsed since the → Big Bang.

→ age; → universe.

Alternative name for the star Hadar, the second brightest star in Centaurus and the tenth brightest star in the sky. → Hadar.

The etymology of Agena is not clear. Some sources have suggested L. a genu "by the knee," but it seems dubious.

1) Something such as a chemical substance, organism, or natural force that causes an effect.
2) Somebody who provides a particular service for another.

From L. agentem (nominative agens, genitive agentis), pr.p. of agere "to set in motion, drive, lead, conduct," → act.

Konešgar, from koneš verbal noun of kardan "to do, to make" (Mid.Pers. kardan, O.Pers./Av. kar- "to do, make, build," Av. kərənaoiti "makes," cf. Skt. kr- "to do, to make," krnoti "makes," karma "act, deed;" PIE base k^wer- "to do, to make") + -gar, → -or.

Meteo.: The wind component deviating from the → geostrophic wind in the absence of the → geostrophic balance. In other words, ageostrophic wind is the difference between the true wind and the geostrophic wind.

From negation prefix → a- + → geostrophic; → wind.

1) (v.) To collect or gather into a cluster or mass.
2) (adj.) Gathered together into a cluster or mass.
3a) (n.) A mass of things clustered together.
3b) A rock composed of rounded or angular volcanic fragments (Dictionary.com).

From L. agglomeratus, p.p. of agglomerare "to wind or add onto a ball," from → ad- "to" + glomerare to "wind up in a ball," from glomus (genitive glomeris) "ball of yarn," globus "globe;" PIE *gel- "to make into a ball."

Bargolemidan, from suffix bar- "to, on, upon," + golem, from Lori, Laki golemâ, golama "curd, obtained from milk by coagulation, used to make cheese," Lori golem "stagnating water," Sangesari, Semnâni, Sorxe-yi, Lâsgardi golma, "boll, i.e. the rounded seed capsule of plants such as cotton," + -idan infinitive suffix.