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

The time based on the motion of the → apparent Sun and kept by dividing the day into 24 equal hours.

→ apparent; → solar; → time.

Surrounding or revolving around the Sun, such as circumsolar space, circumsolar dust.

Circumsolar, from → circum- + → solar.

Chemistry: The process by which a solid, gas, or liquid is dispersed homogeneously in a gas, solid, or a liquid.

Verbal noun of → dissolve.

To make a solution of, as by mixing with a liquid; pass into solution.

From L. dissolvere "to loosen up, break apart," from → dis- "apart" + solvere "to loose, loosen, untie," from PIE *se-lu-, from reflexive pronoun *swe- + base *leu- "to loosen, divide, cut apart" (cf. Gk. lyein "to loosen, release, untie," Skt. lunati "cuts, cuts off," lavitram "sickle," O.E. leosan "to lose," leas "loose."

Vâluyidan, infinitive from stem vâlu(y)-, from vâ-→ de- + lu, variant of Mod.Pers. las "loose," lâ "slit, cut," luš "torn," lok "torn, piece," lâc "open, wide open" (→ analysis), from PIE *leu- "to loosen, divide, cut apart."

A period in the evolution of the → solar system when the planets and satellites were in the process of formation.

→ early; → solar; → system.

Same as → Einstein model.

→ Einstein; → solid.

Electrons and atomic nuclei ejected by solar flares, travelling with velocities amounting to a fraction of the velocity of light, and energies mostly in the range 1-100 million → electronvolts (eV), but occasionally as high as 15 billion eVs. Also known as solar → cosmic rays.

Energetic, from Gk. energetikos, from energe-, → energy, + -tikos a suffix, equivalent in meaning to → -ic, occurring in adjectives; → solar; → particle.

Zarrehâ plural of zarré, → particle; xoršidi, → solar; kâružmand from kâruž, → energy, + -mand possession suffix.

Not belonging to the → solar system; outside, or originating outside, the solar system.

→ extra-; → solar.

A planet which belongs to a star other than → Sun, and therefore does not belong to our → solar system; same as → exoplanet.

→ extrasolar; → planet.

A → planatary system around a star other than the Sun. Same as → exoplanetary system .

→ extrasolar; → system.

An observation that provides a particularly narrow, peaked image of a point source. → point spread function.

→ high; → resolution; → observation.

The separation between two detached but adjacent points in an image.

→ image; → resolution.

The amount of radiative energy received from the Sun per unit area per unit time.

Insolation, from L. insolatus p.p. of insolare "to place in the sun," from → in- + sol, → sun, + -ation a suffix denoting action or condition.

Xortâbgiri, from xor "sun," cognate with L. sol→ sun + tâb "light; heat, warmth; illuminating," from tâbidan, tâftan "to shine," tafsidan "to become hot" (Av. tāp-, taf- "to warm up, heat," tafsat "became hot," tāpaiieiti "to create warmth;" cf. Skt. tap- "to spoil, injure, damage; to suffer; to heat, be/become hot," tapati "burns;" L. tepere "to be warm," tepidus "warm;" PIE base *tep- "warm") + giri verbal noun of gereftan "to take, seize" (Mid.Pers. griftan, Av./O.Pers. grab- "to take, seize," cf. Skt. grah-, grabh- "to seize, take," graha "seizing, holding, perceiving," M.L.G. grabben "to grab," from P.Gmc. *grab, E. grab "to take or grasp suddenly;" PIE base *ghrebh- "to seize").

To set or place apart; detach or separate so as to be alone.
Chemistry: To obtain a substance in an uncombined or pure state.
Physics: → isolated system.

Isolate, back-formation from isolated, from Fr. isolé "isolated," from It. isolato, from L. insulatus "made into an island," from insula "island;" maybe from *en-salos "in the sea," from salum "sea."

Vâyutidan, from vâ- denoting "separation" (also "reversal, opposition; repetition; back, backward," variant of bâz-, from Mid.Pers. abâz-, apâc-; O.Pers. apa- [pref.] "away, from;" Av. apa- [pref.] "away, from," apaš [adv.] "toward the back;" cf. Skt. ápāñc "situated behind") + Mid.Pers. yut "separate, different," Mod.Pers. jodâ "separate, apart;" Av. yuta- "separate, apart" + -idan infinitive suffix.

Set apart or separated from others or other things.

Past participle of → isolate.

A galaxy that is not a member of a dense aggregate. In other words, a galaxy that is formed in a low galactic density environment and has evolved without major interactions with other galaxies of similar mass.

→ isolated; → galaxy.

Massive star formation outside → OB associations. Recent observational findings suggest that → massive star formation is a collective process. In other words, massive stars form in → cluster environments and the mass of the most massive star in a cluster is correlated with the mass of the cluster itself. Nevertheless, other observational results give grounds for supposing that massive stars do not necessarily form in clusters but that they can be formed as isolated stars or in very small groups. According to statistical studies nearly 95% of Galactic → O star population is located in clusters or OB associations. This means that a small percentage, about 5%, of high mass stars may form in isolation. Isolation is meant not traceable to an origin in an OB association. This definition therefore excludes → runaway massive stars, which are thought to result from either dynamical interaction in massive dense clusters, or via a kick from a → supernova explosion in a → binary system. Alternatively, isolated massive star has been defined as follows: An O-type star belonging to a cluster whose total mass is < 100 Msun and moreover is devoid of → B stars (Selier et al. 2011, A&A 529, A40 and references therein).

→ isolated; → massive star; → formation.

A → neutron star which does not belong to a → binary system, does not have radio emission, and is not surrounded by a progenitor → supernova remnant. INSs appear to be thermally cooling with no emission outside the → soft X-ray band, except for faint optical/UV counterparts. Although these properties are similar to those of → compact central object (CCO)s, they are a distinct class because they lack any observable associated supernova remnant or nebula. There are presently seven confirmed INSs (sometimes referred to as The Magnificent Seven), six of which have measured weakly modulated X-ray pulsations with periods between 3 s and 11 s, much longer than those of CCOs (A. K. Harding, 2013, Front. Phys. 8, 679).

→ isolated; → neutron; → star.

Thermodynamics: A system which has no exchange of energy or matter with surroundings. The internal energy of such a system remains constant. → closed system; → open system.

→ isolated; → system.

An act or instance of isolating; the state of being isolated.

Verbal noun of → isolate.