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

One of the two coordinates in the → ecliptic system; the angle measured eastwards along the ecliptic from 0° to 360°, with the origin at the → vernal equinox.

→ ecliptic; → longitude.

The plane of Earth's orbit around the Sun.

→ ecliptic, → plane.

A catalog of fields along the → ecliptic observed by the → K2 mission. The catalog is hosted at the → Mikulski Archive for Space Telescopes (MAST).

→ ecliptic; → plane; → input; → catalogue.

Either of the two points on the celestial sphere that are 90° above and below the plane of ecliptic. The north ecliptic pole lies in → Draco, and the south ecliptic pole in → Dorado. Due to → precession, the → celestial pole moves in a circle around the ecliptic poles once every 25,800 years.

→ ecliptic, → pole.

Coordinate system with the ecliptic as the fundamental plane.

→ ecliptic; → system.

A combining form meaning "house, household, environment, nature, natural habitat."

Ultimately from Gk. oikos "house," cognate with L. villa "country house, farm," related to vicus "village, group of houses; " cf. Av. vis- "homestead, community;" O.Pers. viθ- "house, royal house, farm;" Mid.Pers. wis "village;" dialectal Pers. wiš-, vīš- "to set (of Sun)," wīs- "to enter" (Cheung 2007); Skt. viś- "settlement, house, tribe, people;" Goth. weihs "village;" Lith. viešpats "master of the house;" PIE *ueik'- "to settle (down)."

Bum-, from bum "region, land, a mansion or place where one dwells in saftey; nature, disposition;" Mid.Pers. bûm "land, earth, country;" O.Pers. būmi- "place of being/living, land, region;" Av. būmī- "earth," from bav- "to be, become, take place;" cf. Skt. bhūmi- "land, region;" PIE *bheu- "to be, come into being, become" (cf. Gk. phu- "become," phuein "to bring forth, make grow;" L. fui "I was" (perf. tense of esse), futurus "that is to be, future;" Ger. present first and second person sing. bin, bist; E. to be; O.Ir. bi'u "I am;" Lith. bu'ti "to be;" Rus. byt' "to be").

1) The scientific discipline that is concerned with the relationships between living organisms and their past, present, and future environments.
2) The study of the damaging effects of modern civilisation on the environment, with the aim of prevention or reversal through conservation.

→ eco- + → -logy.

1) Pertaining to the production, distribution, and use of income, wealth, and commodities.
2) Of or relating to the science of economics.
3) Pertaining to an economy, or system of organization or operation, especially of the process of production (Dictionary.com).

Adjective, from → economics.

An increase in the output that an economy produces over a period of time.

→ economic; → growth.

1) Avoiding waste or extravagance; thrifty.
2) → economic.

→ economic; → -al.

The science that deals with description and analysis of the production, distribution, and consumption of goods and services.

From L. oeconomicus "well ordered," from Gk. oikonomikos "practiced in the management of a household or family," from oikonomia, from oiko- "house," → eco-, + -nomia "rule, law," → -nomy; + → -ics.

Bum, → eco- + -dât, → -nomy, + -ik, → -ics.

1) To practice economy; avoid waste or extravagance.
2) To manage economically; use sparingly or frugally (Dictionary.com).

From econom(y), → economy, + → -ize.

1) Thrifty and efficient use of material resources of a community, society, or household; frugality in expenditures.
2) An act or means of thrifty saving; a saving.
3) The management of the resources of a community, country, etc., especially with a view to its productivity (Dictionary.com).

From M.Fr. economie, → economics.

Bumdât, back formation from bumdâti, → economic.

The fabrication of a stable, enduring → ecosystem on a lifeless planet. It is the last stage of a → terraforming process.

From → eco- "house, dwelling place," + poiesis a combining form meaning "making, formation; poetry," from Gk. poesy, from poiein "to make, compose." Coined by Robert Hall Haynes (1931-1998), a Canadian geneticist and biophysicist.

Bum-âfarini, literally "creating environment," from bum "region, land," → eco- + âfarini "creation," from âfaridan, âfarin- "to create," from Mid.Pers. âfridan, âfrin- "to praise, bless; create," ultimately from Proto-Iranian āfrīta-, from prefixed frī- "to praise; to like;" cf. Av. frāy- "to satisfy, propitiate, pray;" Skt. prī- "to gladden, show favor to," prīta- "glad;" Gk. praus "gentle."

The space around a star in which a planet would experience external conditions that are not incompatible with the existence of life.

Ecosphere, from eco-, → ecology, + → sphere.

Bumsepehr, from bum "eco-," → ecology, + sepehr, → sphere.

Any geographic area that includes all of the organisms and nonliving parts of their physical environment.

→ ecology; → system.

Same as → Eddington parameter.

→ Eddington limit; → factor.

The theoretical upper limit of → luminosity at which the → radiation pressure of a light-emitting body would exceed the body's → gravitational attraction. A star emitting radiation at greater than the Eddington limit would break up. The Eddington luminosity for a non-rotating star is expressed as: L_Edd = 4πGMm_pcσ_T^-1, where G is the → gravitational constant, M the star mass, m_p the → proton mass, c the → speed of light, and σ_T the → Thomson cross section. It can also be written as L_Edd = 4πGMcκ^-1, where κ is the → opacity. In terms of solar mass, the Eddington limit can be expressed by: L_Edd = 1.26 × 10³⁸ (M/Msun) erg s^-1. See also → rotational Eddington limit.

Named after Arthur Stanley Eddington (1882-1944), prominent British astrophysicist; → limit.

Same as → Eddington limit.

→ Eddington limit; → luminosity.

A → dimensionless parameter indicating the degree to which a star is close to the → Eddington limit. It is expressed as Γ = L / L_Edd = κ L / (4πGMc), where L and M are the star luminosity and mass respectively, κ is the opacity, c the speed of light, and G the → gravitational constant. At the Eddington limit, Γ = 1, the star would become unbound. Because stellar luminosity generally scales with a high power of the stellar mass (L∝ M^3-4), → massive stars with M larger than 10 Msun generally have electron Eddington parameters of order Γ ≅ 0.1-1.

After Arthur Stanley Eddington (1882-1944), prominent British astrophysicist; → parameter.