retrograde

en-adj

retrograde (comparative more retrograde, superlative most retrograde)

more retrograde (comparative)
most retrograde (superlative)

The adjective is derived from Middle English retrograd, retrograde (“of a planet: appearing to move in a direction opposite to the order of the zodiac signs, retrograde; unfortunate”), from Middle French retrograde and Old French retrograde (“of a celestial object: appearing to move backwards; moving backwards; reverse; palindromic; opposed to change”) (modern French rétrograde), and from their etymon Latin retrōgradus (“of a celestial object: appearing to move backwards”) (compare Late Latin retrōgradus (“reverse; palindromic”)), from retrō (“back, backwards; behind; before, formerly”) + gradus (“pace, step”). By surface analysis, retro- + -grade.
The adverb and noun are derived from the adjective.

cog

/ˈɹɛtɹə(ʊ)ɡɹeɪd/

/ˈɹɛtɹəˌɡɹeɪd/

retrògrad

reverting to an inferior or less developed state — see also declining, regressing

Of a celestial body orbiting another: in the opposite direction to the orbited body's spin.

retrograde

of a celestial body orbiting another: in the opposite direction to the orbited body’s spin

Mercury retrograde

The inauspicious connotations of Mercury retrograde are actually quite old, evidenced in an ancient branch of astrology known as horary astrology.

2018 March 22, Wilder Davies, “Mercury Is Entering Retrograde Again. This Is Why So Many People Care”, in Time:

(also astrology, often postpositive) Of a celestial body: seeming to move across the sky in the opposite direction from its ordinary movement.

ретрограден

of a celestial body: seeming to move across the sky in the opposite direction from its ordinary movement


retrograde

en-verb

retrograde (third-person singular simple present retrogrades, present participle retrograding, simple past and past participle retrograded)

retrogrades (present singular third-person)
retrograding (participle present)
retrograded (participle past)
retrograded (past)

From Middle French retrograder (“to (cause to) go back, return; to (cause to) move backwards; of a celestial object: to show retrograde motion; to date to an earlier period”) (modern French rétrograder), and from its etymon Latin retrōgradī (“to go or step back or backwards; of a celestial object: to show retrograde motion”) (compare Late Latin retrogradare, retrogradari, retrogredere), from retrō (“back, backwards; behind; before, formerly”) + gradior (“to step, walk; to advance, go”) (ultimately from Proto-Indo-European *gʰredʰ- (“to go; to walk”)).

der

/ˈɹɛtɹə(ʊ)ɡɹeɪd/

/ˈɹɛtɹəˌɡɹeɪd/

(astrology, astronomy) Of a celestial body, especially a planet: to show retrogradation; to seem to move across the sky in the opposite direction from its ordinary movement.

perääntyä

of a celestial body: to show retrogradation


saxum

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(astronomy) a boulder, in geographic names on asteroids


blazar

Blend of B + L + Lac + quasar. Coined by astronomer Edward Spiegel in 1978 from BL Lac object and quasar, punning blazing from its optical presentation compared to usual quasars. Analyzable as blaze + -ar.

coin

supermassive black hole
supermassive black hole

(astronomy) A very compact quasar, associated with a supermassive black hole at the center of an active galaxy.

blasaari

astronomy: a very compact quasar, associated with a supermassive black hole

(astronomy) An object which is either an optically violent variable quasar (OVV quasar) or a BL Lac object or which has properties of both.


globular

From French globulaire or Medieval Latin globulāris.


eccentric

From Middle French excentrique, from Medieval Latin eccentricus, from Ancient Greek ἔκκεντρος (ékkentros, “not having the earth as the center of an orbit”), from ἐκ (ek, “out”) + κέντρον (kéntron, “point”). Equivalent to ex- + -centric.

der

(geometry, astronomy) A circle not having the same centre as another.


coordinate

/kəʊˈɔːdɪnɪt/

From Medieval Latin coordinātus, past participle of coordinare (“arrange together”), from Latin co- (“together”) + ordinare (“arrange”), equivalent to co- + ordinate. See ordain and ordinate.

Give me your coordinates and we'll come and rescue you.

(mathematics, cartography, astronomy) A number representing the position of a point along a line, arc, or similar one-dimensional figure.

koördinaat

mathematics, cartography: a number representing the position of a point along a line, arc, or similar one-dimensional figure


phase

From New Latin phasis, from Ancient Greek φάσις (phásis, “an appearance”), from φάω (pháō, “to shine”); compare phantasm and see face.

vaihe

rugby union: period of play between breakdowns

the phases of the moon

(astronomy) A particular appearance or state in a regularly recurring cycle of changes with respect to quantity of illumination or form, or the absence, of its enlightened disk. Illustrated in Wikipedia's article Lunar phase.

փուլ

astronomy: particular appearance or state in a regularly recurring cycle


trajectory

/tɹəˈd͡ʒɛktəɹi/

From New Latin trāiectōria f (“trajectory”) (used by Newton), the feminine of trāiectōrius (“of or pertaining to throwing across”), from Latin trāiectus (“thrown over or across”), past participle of trāiciō, from trans- (“across, beyond”) (see trans-) + iaciō (“to throw”) (from Proto-Indo-European *(H)yeh₁- (“to throw, impel”)). Middle French and Middle English had trajectorie (“end of a funnel”), from Latin trāiectōrium.

(astronomy, space science) The path of a body as it travels through space.


ma

(astronomy, usually in the plural) Abbreviation of milli-arcsecond.


giant

/ˈd͡ʒʌɪ.ənt/

[ˈd͡ʒəɪ̯(ə)nt]

From Middle English geaunt, geant, from Old French geant, gaiant (Modern French géant) from Vulgar Latin *gagās, gagant-, from Latin gigās, gigant-, from Ancient Greek γίγας (gígas, “giant”) Cognate to giga- (“1,000,000,000”). Displaced native Old English ent. Compare Modern English ent (“giant tree-man”).

(astronomy) A star that is considerably more luminous than a main sequence star of the same temperature (e.g. red giant, blue giant).


axle

From Middle English axil, in turn a combination of Old English eax and Old Norse ǫxull.

Axle in the Encyclopædia Britannica (11th edition, 1911)

the Sun’s axle


apoapsis

en-noun

apoapsis (plural apoapsides or apoapsises or apoapses)

apoapsides (plural)
apoapsises (plural)
apoapses (plural)

(astronomy) The point of a body's elliptical orbit about the system's centre of mass where the distance between the body and the centre of mass is at its maximum.


periapsis

periapsis (plural periapsides or periapsises or periapses)

periapsides (plural)
periapsises (plural)
periapses (plural)

LL-Q1860 (eng)-Flame, not lame-periapsis.wav

1983, Richard O. Fimmel, Laurence Colin, Eric Burgess, Pioneer Venus, NASA SP-461, page 109,
Figure 5-19. Sun-Venus-Orbiter geometry illustrates how the periapsis moves around the planet during the Venusian sidereal year to sample day and night hemispheres. Because the planet rotates in a retrograde direction, it takes more than one Venusian sidereal year for periapsis to move over all longitudes of the planet (as explained in text).

We don't always want to burn near periapsis. Suppose we want to change the height at periapsis. The most efficient place to change the radius of periapsis is at apoapsis. Consider applying #92;Deltav at some other point in the orbit. In this case both periapsis and apoapsis will change. If we apply the #92;Deltav tangentially at apoapsis, all of the #92;Deltav will go into changing periapsis, and vice versa.

2001, D. A. Vallado, Fundamentals of Astrodynamics and Applications, Springer, page 325:

2004, R. S. Saunders, et al., Mars Odyssey Mission, C. T. Russell (editor), 2001 Mars Odyssey, Kluwer Academic Publishers, page 34,
The main aerobraking phase began once the point of the spacecraft's periapsis had been lowered to within 110 km above the Martian surface.

(astronomy, astrophysics) The point of a body's (elliptical) orbit in a 2-body gravitational system such that the distance between the two bodies (measured from their respective centres of mass) is at its minimum.


aphelion

aphelion (plural aphelia or (deprecated) aphelions)

aphelia (plural)
aphelions (plural proscribed)

A Greek form of New Latin aphēlium (whence English aphelium, now displaced), from Ancient Greek ἀπο- (apo-, prefix meaning ‘away, from, off’) + ἥλῐος (hḗlĭos, “the sun”) (ultimately from Proto-Indo-European *sóh₂wl̥ (“the sun”)) + -ον (-on, suffix forming some nouns), modelled after New Latin apogaeum (“apogee”).
The plural form aphelia is from aphelion + -a (plural form of the suffix -on).

der

[I]t follows from the theory of gravity, that the aphelia of Mercury, Venus, the Earth, and Mars, slightly progress.

1837, William Whewell, “The Inductive Epoch of Newton—Discovery of the Universal Gravitation of Matter, according to the Law of the Inverse Square of the Distance”, in History of the Inductive Sciences, from the Earliest to the Present Times. […], volume II, London: John W[illiam] Parker, […]; Cambridge, Cambridgeshire: J. and J. J. Deighton, →OCLC, book VII (History of Physical Astronomy), page 170:

(astronomy, also figuratively) The point in the elliptical orbit of a comet, planet, or other astronomical object, where it is farthest from the Sun.

أَوْج

point in the elliptical orbit of a planet where it is farthest from the Sun


equation

From Old French, from Latin aequātiō (“an equalizing”).
Morphologically equate + -ion

(astronomy) A small correction to observed values to remove the effects of systematic errors in an observation.


dark matter

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dark matter
en:Fritz Zwicky
en:Vera Rubin

Calque of German Dunkle Materie, from dunkel (“dark”) and Materie (“matter”). Coined by Swiss astronomer Fritz Zwicky in German in 1933, to account for the apparent mass needed to account for galaxy clusters, where the mass of luminous matter did not add up to enough of a gravitational effect, inferring nonluminous matter must exist to account for the missing mass. The term gained new popularity due to the missing mass found in galaxies to account for galaxy rotation curves discovered by Vera Rubin in research published in English in the 1970s.

The evidence for dark matter in galaxies started to accumulate in the mid-1970s. By the following decade it became clear that essentially all galaxies, including our own Milky Way, are surrounded by extensive halos of dark matter.

2001, Susan M. Fitzpatrick, John T. Brue, Carving Our Destiny: Scientific Research Faces a New Millennium:

On large scales like that of clusters of galaxies, gravitational lensing indicates that the dark matter is smoothly distributed, on the average.

2004, L. Bergström, A. Goobar, “Particle Astrophysics and the Dark Sector of the Universe”, in John W. Mason, editor, Astrophysics Update, pages 124–125:

(astronomy, astrophysics, loosely) Matter which cannot be detected by its radiation but whose presence is inferred from gravitational effects.

donker materie

particles of matter that cannot be detected by their radiation

(particle physics, cosmology, strictly) Matter which has mass but which does not readily interact with normal matter except through gravitational effects.


perturbation

en-noun

perturbation (countable and uncountable, plural perturbations)

Borrowed from Middle French perturbation, from Old French perturbacion, from Latin perturbatio.

(countable, astronomy, physics) Variation in an orbit due to the influence of external bodies


Charon

Charon
Charon (disambiguation)
Charon (moon)
Edmond Hamilton
NASA

From Ancient Greek Χάρων (Khárōn). The name of the moon was coined by American astronomer James W. Christy in 1978, in reference to a fictional moon of Pluto in a novel by Edmond Hamilton but also influenced by its similarity to Char, a pet name for Charlene, his wife's name — hence the alternative American pronunciation, which is used at NASA.

coin

(astronomy) The largest of the five moons of Pluto.


Juliet

/ˈd͡ʒuːlɪɛt/

Borrowed from Italian Giulietta, diminutive of Giulia, from Latin Iūlia, feminine of Iūlius, a Roman family name. Cognate with French Juliette.

(astronomy) The sixth moon of the planet Uranus.


Sappho

(astronomy) 80 Sappho, a main belt asteroid.


Im

(astronomy) irregular galaxy with no coherent structure


station

→ Hindi: स्टेशन (sṭeśan)

→ Irish: stáisiún

→ Malay: stesen

desc

ਸਟੇਸ਼ਨ (sṭeśan)

→ Punjabi: سٹیشن/ਸਟੇਸ਼ਨ (sṭeśan)

→ Scottish Gaelic: stèisean

→ Swahili: stesheni

→ Urdu: سْٹیشَن (sṭeśan), اِسْٹیشَن (isṭeśan)

From Middle English stacioun, borrowed from Anglo-Norman estation, from Latin statiōnem, accusative of statiō (“standing, post, job, position”), whence also Italian stazione. Doublet of stagione. Cognate with Ancient Greek ἵστημι (hístēmi), στάσις (stásis), Old English standan (whence English stand).

(astronomy) The apparent standing still of a superior planet just before it begins or ends its retrograde motion.


trepidation

en-noun

trepidation (countable and uncountable, plural trepidations)

Borrowed from Latin trepidātiō, from trepidō (“be agitated”).

(astronomy, obsolete) A libration of the starry sphere in the Ptolemaic system; a motion ascribed to the firmament, to account for certain small changes in the position of the ecliptic and of the stars.


-ar

Clipping of star.; modelled after the earlier coinages pulsar and quasar.

(astronomy) Used to form names of star types, such as magnetar, collapsar, etc.


-id

From Middle French -ide (like also English -ide), French -ide, and their sources, Latin -id-, -is and Ancient Greek -ῐδ- (-ĭd-), -ῐς (-ĭs).

The Perseid meteor shower's radiant is in the constellation of Perseus.

(astronomy) Forming common names of meteors from their apparent constellation of origin.


late

en-adj

late (comparative later, superlative latest)

later (comparative)
latest (superlative)

From Middle English late, lat, from Old English læt (“slow; slack, lax, negligent; late”), from Proto-West Germanic *lat, from Proto-Germanic *lataz (“slow, lazy”). By surface analysis, deverbal from let.

der

(astronomy) Of a star or class of stars, cooler than the sun.


Alexandra

en-proper noun

Alexandra (countable and uncountable, plural Alexandras)

/ˌæ.lɪɡˈzæn.dɹə/

/ˌæ.lɪɡˈzɑn.dɹə/

/ˌæ.lɪɡˈzɑːn.dɹə/

54 Alexandra
Alexandra
Alexandra, New Zealand
Queen Alexandra

From Ancient Greek Ἀλεξάνδρα (Alexándra), from ἀλέξω (aléxō, “I defend”) + ἀνδρ- (andr-, stem of ἀνήρ (anḗr, “man”)). Feminine form of Alexander.
The community in Prince Edward Island is named after Queen Alexandra (1844–1925).

af

stem of <i class="Polyt mention" lang="grc">ἀνήρ</i> (anḗr, “man”)

(astronomy) 54 Alexandra, a main belt asteroid; named for German explorer Alexander von Humboldt.


morning star

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From morning + star. Compare West Frisian moarnstjer, Dutch morgenster, German Morgenstern, Swedish morgonstjärna, Icelandic morgunstjarna. Application to Satan derives, like the corresponding sense of Lucifer (which see), from what is probably a misinterpretation of Isaiah 14:12 (NIV: "How you have fallen from heaven, morning star, son of the dawn! You have been cast down to the earth, you who once laid low the nations!").

The evening star is the morning star. (Hesperus is Phosphorus.)

Morn in the white wake of the morning star / Came furrowing all the orient into gold.

1847, Alfred Tennyson, “Part III”, in The Princess: A Medley, London: Edward Moxon, […], →OCLC, page 47:

1979, Paul Williams and Kenneth Ascher, “The Rainbow Connection”, The Muppet Movie, Henson Associates and ITC Entertainment
Who said that every wish would be heard and answered / When wished on the morning star? / Somebody thought of that, and someone believed it / And look what it's done so far.

(astronomy) The planet Venus as observed in the eastern sky around dawn.


dwarf

From Middle English dwergh, dwerw, dwerf, from Old English dweorg, from Proto-West Germanic *dwerg, from Proto-Germanic *dwergaz.
Cognate with Scots dwerch; Old High German twerc (German Zwerg); Old Norse dvergr (Swedish dvärg); Old Frisian dwirg (West Frisian dwerch); Middle Low German dwerch, dwarch, twerg (German Low German Dwarg, Dwarch); Middle Dutch dwerch, dworch (Dutch dwerg).
The Modern English noun has undergone complex phonetic changes. The form dwarf is the regular continuation of Old English dweorg, but the plural dweorgas would have given rise to dwarrows and the oblique stem dweorge- would have led to dwery. These forms are sometimes found as the nominative singular in Middle English texts and in English dialects. A parallel case is that of Old English burg giving burgh, borough, burrow, bury.

dwarf standing on the shoulders of giants


inferior

en-adj

inferior (comparative more inferior, superlative most inferior)

more inferior (comparative)
most inferior (superlative)

Borrowed from Latin īnferior (“lower in situation or place”), comparative of īnferus (“below, underneath”).

bor

the inferior part of a meridian

Located below:
(astronomy) Below the horizon.

the inferior or interior planets; an inferior conjunction of Mercury or Venus

(astronomy) Nearer to the Sun than the Earth is.


superior

/sʉːˈpɪə.ɹiː.ə/

From Middle English, borrowed from Old French superiour, from Latin superior (“higher, upper”).

(astronomy, of a planet in the Solar System) Having a wider orbit around the Sun; typically with respect to the Earth.


waning gibbous

(astronomy) More than half full in phase, but growing smaller.


Persephone

From Ancient Greek Περσεφόνη (Persephónē).

(astronomy) 399 Persephone, a main belt asteroid.


Demeter

From Ancient Greek Δημήτηρ (Dēmḗtēr), from γῆ (gê, “earth”) + μήτηρ (mḗtēr, “mother”).

(astronomy) 1108 Demeter, a main belt asteroid.


Orion

From Middle English Orioun, from Latin Ōrīōn, from Ancient Greek Ὠρίων (Ōríōn), speculatively from Akkadian 𒌋𒊒𒀭𒈾 (Uru-anna, “heaven's light”), though without any firm evidence.

der

(astronomy) A constellation on the celestial equator close to Gemini and Taurus, containing the stars Betelgeuse and Rigel.


Europa

From Ancient Greek Εὐρώπη (Eurṓpē), a character name in Greek mythology.
Doublet of Europe.

(astronomy) 52 Europa, a main belt asteroid; not to be confused with the Jovian moon.


apogee

perigee

antonym(s) of “a point in an orbit around the Earth”

perigee is the etymological antonym

(antonym(s) of “highest point”): nadir, perigee

From Middle French apogée, from Latin apogaeum, apogēum, from Ancient Greek ἀπόγειον (apógeion, “away from Earth”), from ἀπό (apó, “away”) + γῆ (gê, “Earth”).

uder

(astronomy) The point, in an orbit about the Earth, that is farthest from the Earth: the apoapsis of an Earth orbiter.

Conjunctions of I and II [Io and Europa] occur when they are near perigee and apogee respectively; conjunctions of II and III [Europa and Ganymede] occur when II [Europa] is near perigee.

1995, John H. Rogers, The Giant Planet Jupiter, Cambridge University Press, →ISBN, page 335:

The resolution of the images obtained by this American probe [Messenger] will depend on its altitude [above Mercury] at any one time: about ten meters at perigee (200km altitude), but only one 1 km at apogee (15000km).

2002, Serge Brunier, Solar System Voyage, Cambridge University Press, →ISBN, page 36:

[Nereid’s] apogee—farthest point from Neptune—is five times the distance of its perigee—its closest point.

2010, Ruth WalkerMary M. Shaffreyet al., Exploring Space: The High Frontier, Jones & Bartlett Learning, →ISBN, page 129:

(astronomy, more generally) The point, in an orbit about any planet, that is farthest from the planet: the apoapsis of any satellite.


apse

From Latin apsis, hapsis, from Ancient Greek ἁψίς (hapsís, “arch, vault”), from ἅπτω (háptō, “I bind, join”).

der

(astronomy, obsolete) Obsolete form of apsis.; The nearest and furthest points to the centre of gravitational attraction for a body in orbit. More usually called an apsis.


corona

en-noun

corona (plural coronas or coronae or (obsolete) coronæ)

coronas (plural)
coronae (plural)
coronæ (obsolete plural)

→ Japanese: コロナ (korona)

The noun is borrowed from Latin corōna (“crown; garland, wreath”), from Ancient Greek κορώνη (korṓnē, “type of crown; curved object (door handle, tip of a bow, stern of a ship, etc.)”), from Proto-Indo-European *(s)ker- (“to turn, bend”). The English word is a doublet of crown, korona, koruna, krona, króna, and krone.
The plural form coronae is borrowed from Latin corōnae.
The verb is derived from the noun.

laki

upper or crownlike portion of certain parts of the body

kruunu

appendage of an organism that resembles a crown or corona

My investigations seem to prove conclusively that the theoretical corona is caused by light emitted and reflected from streams of matter ejected from the Sun by forces which, in general, act along lines normal to the surface. These forces are most active near the center of each Sun-spot zone.

1890 April 11, J[ohn] M[artin] Schaeberle, “A Mechanical Theory of the Solar Corona”, in Monthly Notices of the Royal Astronomical Society, volume I, number 6, London: Royal Astronomical Society, […], →ISSN, →OCLC, page 372:

The corona is a high-temperature portion of the Sun's outer atmosphere, beginning slightly above the visible surface and extending hundreds of thousands of kilometers, or further, into interplanetary space.

2010, Leon Golub, Jay M[yron] Pasachoff, “Introduction”, in The Solar Corona, 2nd edition, Cambridge, Cambridgeshire: Cambridge University Press, →ISBN, page 1:

The luminous plasma atmosphere of the Sun (the solar corona) or other star, extending millions of kilometres into space, most easily seen during a total solar eclipse.

korona

luminous plasma atmosphere of the Sun or other star

The area density of impact craters on the surfaces of the coronas suggests that the episode of tidal heating occurred approximately one billion years ago[…].

2007, Gunter Faure, Teresa M. Mensing, “Uranus: What Happened Here?”, in Introduction to Planetary Science: The Geological Perspective, Dordrecht: Springer, →ISBN, page 379, column 1:

(also geology) An oval-shaped astrogeological feature, present on both the planet Venus and Uranus's moon Miranda, probably formed by upwellings of warm material below the surface.


geyser

desc

→ Bengali: গিজার (gijar, “water boiler”)

→ Hindi: गीज़र (gīzar, “water heater”)

From the name of a particular Icelandic geyser which is mentioned as early as the 1760s in The Annual Register, as “Geyser, a wonderful spring in the valley of Haukadal”. From Geysir (“Gusher”), the Icelandic name of the hot spring in Iceland (see Wikipedia), from the verb geysa (“to gush”), from Old Norse geysa (“to gush”). Doublet of gusher.

(planetology, geology, volcanology) A boiling natural spring which throws forth jets of water, mud, etc., at frequent intervals, driven upwards by the expansive power of steam.

fons calidae atque alte exsilientis aquae


quasar

Blend of quasi- + stellar, from quasi-stellar radio source. Coined by American astrophysicist Hong-Yee Chiu in 1964 in an article in Physics Today. Analyzable as quasi- + -ar.

coin

(astronomy) An extragalactic object, starlike in appearance, that is among the most luminous and (putatively) the most distant objects in the universe.


rill

From or akin to West Frisian ril (“rill; a narrow channel”), Dutch ril (“rill; gully; trench; watercourse”), German Low German Rille, Rill (“a small channel; brook; furrow”), German Rille (“a groove; furrow”).

cog

(planetology) Alternative form of rille.


synod

From Ancient Greek σύνοδος (súnodos, “assembly, meeting”) – from σύν (sún, “with”) (English syn-) + ὁδός (hodós, “way, path”).
Compare also with the term סַנְהֶדְרִין (“sunédrion”) common throughout Hebrew Talmudic literature.

bor

(astronomy) A conjunction of two or more of the heavenly bodies.


umbra

en-noun

umbra (plural umbras or umbrae or (obsolete) umbræ)

umbras (plural)
umbrae (plural)
umbræ (obsolete plural)

Borrowed from Latin umbra (“shadow”). Doublet of umber.

The fully shaded inner region of a shadow cast by an opaque object.

(astronomy) The area on the earth or moon experiencing the total phase of an eclipse.

(astronomy) The central region of a sunspot.


oblique sphere

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(astronomy, geography) The celestial or terrestrial sphere when its axis is oblique to the horizon of the place; or as it appears to an observer at any point on the earth except the poles and the equator.


crater

First coined 1613, from Latin crātēr (“basin”), from Ancient Greek κρᾱτήρ (krātḗr, “mixing-bowl, wassail-bowl”).

der

(astronomy) A hemispherical pit created by the impact of a meteorite or other object.


culmination

en-noun

culmination (countable and uncountable, plural culminations)

Borrowed from French culmination, from culminer, or from Medieval Latin culminatus + -tion.
Morphologically culminate + -ion

(astronomy) The attainment of the highest point of altitude reached by a heavenly body; passage across the meridian; transit.

բարձրակետ

astronomy: attainment of the highest point


dichotomy

dichotomy (countable and uncountable, plural dichotomies)

Audio (GA)

Audio (AU)

From Ancient Greek διχοτομία (dikhotomía, “dichotomy”).

der

The Ides of Januarius indeed, the preceding month, must have fallen on March 1 at midnight, two days before the first dichotomy of the mean new moon of that month, March 3 at midnight.

1854, Edward Greswell, Origines Kalendariæ Italicæ: Tables of the Roman Calendar, volume 1, page 261:

(astronomy) A phase of the moon when it appears half lit and half dark, for example at the quadratures.


elevation

en-noun

elevation (countable and uncountable, plural elevations)

/ˌɛlɪˈveɪʃən/

From Old French elevation, from Latin elevatio, equal to elevate + -ion.

the elevation of the pole, or of a star

(astronomy) The distance of a celestial object above the horizon, or the arc of a vertical circle intercepted between it and the horizon; altitude.


elongation

elongation (countable and uncountable, plural elongations)

LL-Q1860 (eng)-Flame, not lame-elongation.wav

Borrowed from Late Latin elongatio, elongationem.

the elongation of Venus

(astronomy) The angular distance of a planet from the sun.


equator

From Late Latin (circulus) aequator (diei et noctis).

bor

(astronomy) A similar great circle on any sphere, especially on a celestial body, or on other reasonably symmetrical three-dimensional body.


granulation

en-noun

granulation (countable and uncountable, plural granulations)

LL-Q1860 (eng)-Flame, not lame-granulation.wav

From Late Latin grānulum (“granule”) + -ation. Attested earlier than granule and granulate. By surface analysis, granulate + -ion.

suffix

(astronomy) A bright, transient granular marking on the Sun's photosphere.


node

→ Irish: nód

From Middle English node, borrowed from Latin nōdus. Doublet of knot, knout, and nodus.

(astronomy) The point where the orbit of a planet, as viewed from the Sun, intersects the ecliptic. The ascending and descending nodes refer respectively to the points where the planet moves from South to North and N to S; their respective symbols are ☊ and ☋.

solmu

astronomy: where the orbit of a planet intersects the ecliptic


Pegasus

From Late Middle English Pegase, Pegasus, from Latin Pēgasus, from Ancient Greek Πήγασος (Pḗgasos), traditionally associated with πηγή (pēgḗ, “spring, fountain, fountain fed by a spring”), especially used to denote springs of Ocean, where Perseus killed Medusa, from whose blood Pegasus sprang. Some have dismissed this as folk etymology and suggest a pre-Greek origin because of the -ασος suffix. First attested in the 14th century.

Пегас

in Ancient Greek or other European contexts

vernal equinoctial
vernal equinox#English

(Greek mythology) A winged horse fabled to have sprung from the blood of Medusa when she was slain. He is noted for causing, with a blow of his hoof, Hippocrene, the inspiring fountain of the Muses, to spring from Mount Helicon. Bellerophon tamed and rode upon Pegasus when he defeated the Chimaera.

(astronomy) A constellation of the northern sky, near the vernal equinoctial point, representing the winged horse. Its three brightest stars, with the brightest star of Andromeda, form the asterism of the Great Square of Pegasus.


regress

en-verb

regress (third-person singular simple present regresses, present participle regressing, simple past and past participle regressed)

regresses (present singular third-person)
regressing (participle present)
regressed (participle past)
regressed (past)

(verb) From Latin regressus, past participle of regredior (“to go back”), from re- (“back”) + gradior (“to go”).

(intransitive, astronomy) To move in the retrograde direction.


Scylla

From Latin Scylla, from Ancient Greek Σκύλλα (Skúlla).

(astronomy) The main belt asteroid 155 Scylla.


secondary

From Middle English secundarie, from Latin secundārius (“of the second class or quality”), from secundus (whence the English second) + -ārius (whence the English suffix -ary), equivalent to second + -ary; compare the French secondaire, the Italian secondario, the Occitan secundari, the Portuguese secundario, and the Spanish secundario.

der

English numerals#Ordinal numbers
secondary


troll

Partly:
* from Middle English trol (“demon (?); sorcerer (?)”) [and other forms], from Old Norse trǫll (“conjurer, mage; witch”), from Proto-Germanic *truzlą (“supernatural being; demon, fiend; giant; monster”), probably from *trudaną (“to step on; to tread”) + *-ilą (suffix forming agent nouns); and
* borrowed from Norwegian Bokmål troll, Swedish troll, or Danish trold, from Old Norse trǫll (see above).
Doublet of droll and trow.
Cognates
* Danish fortrylle (“to bewitch”), trylle (“to conjure”)
* Icelandic tröll
* Middle High German trol, trolle (“spook, wraith; ogre, monster”)
* Norwegian fortrylle (“to bewitch”), trylle (“to conjure”)
* Swedish trolla (“to conjure”)

der

(astronomy, meteorology) An optical ejection from the top of the electrically active core region of a thunderstorm that is red in colour that seems to occur after tendrils of vigorous sprites extend downward towards cloudtops.


wane

en-verb

wane (third-person singular simple present wanes, present participle waning, simple past and past participle waned)

wanes (present singular third-person)
waning (participle present)
waned (participle past)
waned (past)

From Middle English wanen, wanien, from Old English wanian, wonian, from Proto-West Germanic *wanōn, from Proto-Germanic *wanōną.

The fall of Jack, and the subsequent fall of Jill, simply represent the vanishing of one moon-spot after another, as the moon wanes.

1866, Sabine Baring-Gould, “The Man in the Moon”, in Curious Myths of the Middle Ages:

(intransitive, astronomy) Said of the Moon as it passes through the phases of its monthly cycle where its surface is less and less visible.


mansion

→ Japanese: マンション (manshon)

From Middle English mansioun, borrowed from Anglo-Norman mansion, mansiun, from Latin mānsiō (“dwelling, stopping-place”), from the past participle stem of manēre (“stay”).

der

(Chinese astronomy) One of twenty-eight sections of the sky.


intensity

en-noun

intensity (countable and uncountable, plural intensities)

From intense + -ity. Cf. also Medieval Latin intensitas.


eon

From Latin aeon, from Ancient Greek αἰών (aiṓn, “age, era”).

We live our lives in three dimensions for our threescore and ten allotted years. Yet every branch of contemporary science, from statistics to cosmology, alludes to processes that operate on scales outside of human experience: the millisecond and the nanometer, the eon and the light-year.

2012 January 24, Robert L. Dorit, “Rereading Darwin”, in American Scientist, volume 100, number 1, archived from the original on 2012-11-14, page 23:

(astronomy, geology) A period of one billion (short scale, i.e. 1,000,000,000) years.


perihelion

perihelion (plural perihelia or (deprecated) perihelions)

perihelia (plural)
perihelions (plural proscribed)

PIE word
 *sóh₂wl̥
From perihelium (“perihelion”) (obsolete) + -on (suffix forming nouns) (from Ancient Greek -ον (-on)). Perihelium is borrowed from Late Latin perihelium, from Ancient Greek περι- (peri-, “around; surrounding”), ultimately from Proto-Indo-European *per- (“before, in front; first”)) + ἥλιος (hḗlios, “sun”) (ultimately from Proto-Indo-European *sóh₂wl̥ (“sun”) or a pre-Hellenic language), which was modelled after perigeum (“point in an orbit about the Earth that is closest to the Earth, perigee”).

der

The æquation of the Earth encreaſeth from her Aphelion, until ſhe come to the point where it's greateſt, and from thence it again decreaſeth till ſhe come to her Perihelion, or oppoſite Auge: in like manner it increaſeth from her Perihelion to the point where it's greateſt, and afterwards decreaſeth till ſhe come againe to the Auge or Aphelion, [...]

1656, Vincent Wing, “Of the Annuall Motion of the Earth”, in Astronomia Instaurata: Or, A New and Compendius Restauration of Astronomie. […], London: […] R. and W. Leybourn, for the Company of Stationers, →OCLC, part 1, paragraph 12, page 46:

They [the best astronomers of this age] all agree that the Planets turn in ſo many Ellipſes, of which the Sun is the focus; the reaſon of it is, that they are obſerved to be in ſome points called Perihelia, nearer to the Sun, and, in the oppoſite points call'd Aphelia, farther from it; which could not be, if they mov'd in a perfect circle.

1693 April 4, J. de la Crose [i.e., Jean Cornand de Lacroze], “Letter XIII. To the Honourable Sir Edwin Sadler.”, in Memoirs for the Ingenious. Containing Several Curious Observations in Philosophy, Mathematicks, Physick, Philology, and Other Arts and Sciences. In Miscellaneous Letters. […], volume I, London: […] H. Rhodes […]; and for J. Harris […], →OCLC, page 98:

[I]f Comets were obſerv'd to have to Atmoſphere after their return from the Regions beyond Saturn, before they arrived at their Perihelia again, then indeed this reaſoning were unavoidable; but ſeeing the contrary is evident from Aſtronomical Obſervations, it cannot affect his [William Whiston's] Hypotheſis.

1734, J[ohn] Keill, “A Defence of the Remarks Made on Mr Whiston’s New Theory”, in An Examination of Dr. Burnet’s Theory of the Earth: With Some Remarks on Mr. Whiston’s New Theory of the Earth. […], 2nd edition, London: […] H. Clements, […]; and S. Harding, […], →OCLC, page 319:

The base of the system is that all planets, comets and satellites go through a reversed change of motion, volume, distance and density at their perihelions and aphelions, each orbital revolution: this being effected through reciprocating electric currents or lines that exist and undulate between the planetary bodies, with which currents are used to carry on these planetary changes. These changes continue from perihelion to aphelion, and from aphelion to perihelion again, and are in proportion to the amount of ellipticity in their orbits—the greater the ellipticity the greater the changes.

1893–1894, “Astronomy, Astronomical Symbols, Elements of the Solar System, and Theories Regarding the Planets, According to the Latest and Best Authorities”, in The Statistician and Economist, 17th edition, San Francisco, Calif., New York, N.Y.: L. P. McCarty, published 1893, →OCLC, part IV (The Miscellany), page 575:

This rotational motion could have the axis of minimum moments of inertia nearly aligned with the Sun–Mercury radius vector at every perihelion passage.

1965 November 6, G[iuseppe] Colombo, “Rotational Period of the Planet Mercury [letter]”, in Nature: A Weekly Illustrated Journal of Science, volume 208, number 5010, London: Macmillan and Co.; New York, N.Y.: The Macmillan Company, →DOI, →OCLC, page 575, column 1:

In this case, the rate of advance of the perihelia of their elliptical orbits provides important information about the masses of the neutron stars as well as providing very sensitive tests of general relativity itself.

2003, Malcolm S[im] Longair, “An Introduction to General Relativity”, in Theoretical Concepts in Physics: An Alternative View of Theoretical Reasoning in Physics, 2nd edition, Cambridge, Cambridge: Cambridge University Press, →ISBN, section 17.7 (Advance of Perihelia of Planetary Orbits), page 464:

The longitude of the comet is not usually specified at a particular epoch. Rather, the epoch is given when the comet is at perihelion, the point of its closest approach to the Sun. [...] Note that, as in the case of the planetary elements, we have specified ϖ, the longitude of the perihelion.

2011, Peter Duffett-Smith, Jonathan Zwart, “The Planets, Comets and Binary Stars”, in Practical Astronomy with Your Calculator or Spreadsheet, 4th edition, Cambridge, Cambridgeshire: Cambridge University Press, →ISBN, section 61 (Comets), page 143:

(astronomy) The point in the elliptical orbit of a comet, planet, etc., where it is nearest to the Sun.


perigee

/ˈpɛɹ.ɪ.d͡ʒiː/

LL-Q1860 (eng)-Flame, not lame-perigee.wav

From French périgée via Latin perigeum, perigaeum, ultimately from Ancient Greek περί (perí, “near”) + γῆ (gê, “Earth”).

periapsis

closest point in an orbit about a planet

As the moon wheels around Earth every 28 days and shows us a progressively greater and then stingier slice of its sun-lightened face, the distance between the moon and Earth changes, too. At the nearest point along its egg-shaped orbit, its perigee, the moon may be 26,000 miles closer to us than it is at its far point.

2014 September 7, Natalie Angier, “The Moon comes around again [print version: Revisiting a moon that still has secrets to reveal: Supermoon revives interest in its violent origins and hidden face, International New York Times, 10 September 2014, p. 8]”, in The New York Times:

(astronomy) The point, in an orbit about the Earth, that is closest to the Earth: the periapsis of an Earth orbiter.

երկրամերձ կետ

closest point in an orbit about the Earth

Conjunctions of I and II [Io and Europa] occur when they are near perigee and apogee respectively; conjunctions of II and III [Europa and Ganymede] occur when II [Europa] is near perigee.

1995, John H. Rogers, The Giant Planet Jupiter, Cambridge University Press, →ISBN, page 335:

The resolution of the images obtained by this American probe [Messenger] will depend on its altitude [above Mercury] at any one time: about ten meters at perigee (200km altitude), but only one 1 km at apogee (15000km).

2002, Serge Brunier, Solar System Voyage, Cambridge University Press, →ISBN, page 36:

[Nereid’s] apogee—farthest point from Neptune—is five times the distance of its perigee—its closest point.

2010, Ruth WalkerMary M. Shaffreyet al., Exploring Space: The High Frontier, Jones & Bartlett Learning, →ISBN, page 129:

(astronomy, more generally) The point, in an orbit about any planet, that is closest to the planet: the periapsis of any satellite.


GC

w:General Catalogue of Nebulae and Clusters

(astronomy) Initialism of General Catalogue of Nebulae and Clusters.

Boss General Catalogue
w:Boss General Catalogue

(astronomy) Initialism of Boss General Catalogue.


nova

Feminine nominative singular of Latin novus (“new”). The feminine is used since stella (“star”) is feminine; thus nova is a shortening of nova stella (“new star”), first used in this sense in 1573 by Tycho Brahe.

(astronomy) Any sudden brightening of a previously inconspicuous star.


supernova

en-noun

supernova (plural supernovae or supernovæ or supernovas)

supernovae (plural)
supernovæ (plural)
supernovas (plural)

(astronomy) A powerful and bright explosion of a massive star, which afterwards becomes a neutron star or a black hole, or is destroyed.


Jove

From Middle English Joves, from Latin Iuppiter, Iovis, from Proto-Italic *djowe-, ablative case of *djous, from Proto-Indo-European *dyḗws. Doublet of Dyeus and Zeus.


Sedna

Borrowed from Inuktitut Sitna.
The dwarf planet is named after the goddess.

Scattered beyond the Kuiper Belt is a disk of objects such as Eris and Sedna.

2007, C. Murray, David Brodie, Ice, Rock, and Beauty: A Visual Tour of the New Solar System, page 32:

Brown clicked on a button to have the computer calculate just how far away the object was, and came up with a distance farther than Pluto, even farther than Sedna: about 97 AU. Then he ran some quick calculations to estimate how big the object was, assuming that it was as reflective as Sedna.

2009, Alan Boyle, The Case for Pluto: How a Little Planet Made a Big Difference, page 106:

2010, Rodney S. Gomes, Jean S. Soares, Sedna, 2004 VN112 and 2000 CR105: the tip of an iceberg, Julio A. Fernández, Daniela Lazzaro, Dina Prialnik, Rita Schulz (editors), Icy Bodies of the Solar System: Proceedings of the 263rd Symposium of the International Astronomical Union (IAU S263), page 67,
We review two main scenarios that may have implanted Sedna, 2004 VN112 and 2000 CR105 on their current peculiar orbits.

(astronomy) 90377 Sedna, a trans-Neptunian dwarf planet whose eccentric detached orbit is wholly beyond the Kuiper belt.

Ceres

most likely dwarf planets of the Solar System

(astronomy) Sedna Planitia, a plain on Venus.


Asclepius

Borrowed from Latin Asclēpius, from Ancient Greek Ἀσκληπιός (Asklēpiós).

(astronomy) The Apollo asteroid 4581 Asclepius.


tellurian

Benjamin Martin
Harvard Science Center
Harvard University

[tʰəˈlɝː.iː.ɨ̃n]

From Latin tellūs (“earth, ground; the globe, planet Earth; country, land”), ultimately from Proto-Indo-European *telh₂- (“ground, bottom”), + -ian (suffix meaning "from, related to, or like" when forming an adjective, or "one from, belonging to, relating to, or like" when forming a noun).

suffix

The Second Part of this Orrery I call a Tellurian, [...] becauſe it ſhews moſt accurately and evidently all the Phœnomena ariſing from the Annual and Diurnal Motions of the Earth, in a Terreſtrial Globe full Three Inches in a Diameter; upon which all the Parts of the terraqueous Surface are diſtinctly delineated, [...]

1771, Benjamin Martin, “Of the Tellurian”, in The Description and Use of an Orrery of a New Construction, Representing in the Various Parts of Its Machinery All the Motions and Phoenomena of the Planetary System; […], London: Printed for, and sold by the author, […], →OCLC, page 4:

Among the modern inventions appertaining to astronomy, besides the instruments necessary to correct observation, we may reckon those curious and elegant machines, exhibiting the motions and phenomena of our solar system and its several parts; our orreries, planetariums, tellurians, lunariums, &c., all of which may be considered as extremely interesting and ingenious contrivances.

1823, Edward Nares, “A View of the State of Arts, Sciences, Religion, Laws, Government, &c.”, in [Alexander Fraser Tytler], Thomas Robbins, Tytler’s Elements of General History, Ancient and Modern. […] To which is now Added, A View of the State of Arts, Sciences, Religion, Laws, Government, &c. by the Rev. Edward Nares, D.D. […], Hartford, Conn.: Published by Huntington & Hopkins, →OCLC, page 381:

(astronomy, historical) Alternative spelling of tellurion (“instrument used to show how the rotation of the Earth on its axis and its orbit around the Sun cause day and night and the seasons”)


terrestrial

aerial

antonym(s) of “of, made of, related to, or living or growing on land”

celestial

antonym(s) of “concerned with the world”

/tɪˈɹɛstɹɪ.əl/

/tɪˈɹɛstɹɪ.əl/

/təˈɹɛstɹɪ.əl/

/tɪˈɹɛstɹɪ.əl/

From Middle English terrestrialle, from terrestre or Latin terrestris, from terra (“land, earth, ground”), with the suffix -al.

(astronomy) Of a planet, being composed primarily of silicate rocks or metals; see also terrestrial planet.

maankaltainen

astronomy: being composed primarily of silicate rocks or metals


tellurion

LL-Q1860 (eng)-Flame, not lame-tellurion.wav

From Latin tellūs (“earth, ground; the globe, planet Earth; country, land”) (ultimately from Proto-Indo-European *telh₂- (“ground, bottom”) + -ion (a Latinate suffix used in place of -ian (suffix meaning ‘one from, belonging to, relating to, or like’)), possibly coined by Benjamin Martin (baptized 1705; died 1782), an English lecturer, lexicographer, and maker of scientific instruments: see the quotation.

refn

From the collection of the Harvard Science Center, Harvard University, in Cambridge, Massachusetts, USA.

der

(astronomy, historical) An instrument used to show how the rotation of the Earth on its axis and its orbit around the Sun cause day and night and the seasons.


Artemis

From Ancient Greek Ἄρτεμις (Ártemis). Further etymology is uncertain.

(astronomy) The main-belt asteroid 105 Artemis, discovered in 1868.


variation

en-noun

variation (usually uncountable, plural variations)

/ˌvɛəɹɪˈeɪʃn̩/

/ˌvɛəɹiˈeɪʃn̩/

/ˌvæɹiˈeɪʃn̩/

/ˌvɛɹiˈeɪʃn̩/

From Middle French variation, from Old French variacion, from Latin variātiō, from vary + -ation.

(astronomy) Deviation from the mean orbit of a heavenly body.


ice dwarf

LL-Q1860 (eng)-Flame, not lame-ice dwarf.wav

Farthest from the dim red dwarf Ondeste, the ice dwarf Maisuth has attracted no interest beyond a cursory flyby by automated probe in 1874. No significant resources were noted.

2010, BioWare, Mass Effect 2 (Science Fiction), Redwood City: Electronic Arts, →OCLC, PC, scene: Maisuth, Ondeste System:

(astronomy) An icy planetoid: an astronomical object, such as Pluto, Sedna or (for some authors) Ceres that is large enough to be a world and contains more ice than a typical asteroid.

transneptunian object
transneptunian object

(astronomy) A centaur or transneptunian object.

(astronomy) An astronomical object that is larger than the core of a typical comet and icier than a typical asteroid.


Clio

(astronomy) 84 Klio, a main belt asteroid.


NEC

near-Earth comet
near-Earth comet#English

(astronomy) Initialism of near-Earth comet.


active galaxy

(astronomy) A galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy.


Varuna

(astronomy) A Kuiper belt object, once thought to be possibly a dwarf planet.


heliocentric

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a heliocentric coordinate system

a heliocentric orbit

To make the Catalogue of Eclipses, as also the Table of the Parallaxes of [Jupiter], it was necessary first to make a Table of [Jupiter]' Heliocentrick places, to which the Parallaxes being applied, give the Geocentrick.

1685, J. Flamsteed, Philosophical Transactions, XV, p. 1217:

Apollyon, who, as god of the sun, has a certain stake in the matter, teaches the Prior the truth of what the Greeks, Pythagoras' disciples, knew many years before— the nature of the heliocentric (or pyrocentric) planetary system.

1967, Gerald Cornelius Monsman, Pater's Portraits: Mythic Pattern in the Fiction of Walter Pater, pages 187–188:

(astronomy) Having the sun at the center/centre; usually in reference to a coordinate system or orbit. [from 17th c.]

(cosmology) Of or relating to heliocentrism.


geocentric

/ˌdʒiːəʊˈsɛntɹɪk/

(cosmology) Of or relating to geocentrism, an obsolete cosmology which placed the Earth at the center of the universe.


solar prominence

solar prominence (plural solar prominences)

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(astronomy) Any of the large eruptions of luminous hydrogen gas that rise thousands of kilometers above the chromosphere of the Sun.


outflow

outflow (countable and uncountable, plural outflows)

LL-Q1860 (eng)-Flame, not lame-outflow.wav

From Middle English outflowen, from late Old English ūtflōwan (attested in the past tense as ūt flēow), equivalent to out- + flow. The noun is derived from the verb.

active galactic nucleus
active galactic nucleus

(astronomy) A stream of gaseous material emanating from an active galactic nucleus.


magnitude

magnitude (countable and uncountable, plural magnitudes)

From Latin magnitūdō (“greatness, size”), magnus + -tūdō.

(astronomy) A logarithmic scale of brightness defined so that a difference of 5 magnitudes is a factor of 100.

(uncountable) The apparent brightness of a star, with lower magnitudes being brighter; apparent magnitude

Observations in the infrared domain allow one to penetrate the ~25-30 magnitudes of extinction present at visible wavelengths.

2005, Andreas Eckart et al., The Black Hole at the Center of the Milky Way, →ISBN, page 71:

(countable) A ratio of intensity expressed as a logarithm.


aureole

/ˈɔː.ɹiː.əʊl/

From Middle English aureole, from Old French aureole, from Medieval Latin aureola (corona) ("golden (crown)").


CV

CV (countable and uncountable, plural CVs)

Abbreviation
* (anime, Japanimation): From Japanese CV (CV), from English character+voice
* (aircraft carrier): Initialism of cruiser (“croiseur”) + French voler (“to fly”).

initialism of

cataclysmic variable
cataclysmic variable#English

(astronomy) Initialism of cataclysmic variable.


Xena

Xena (disambiguation)
en:Xena: Warrior Princess

The lead character in the television series Xena: Warrior Princess (1995–2001) was the inspiration for the dwarf planet's nickname and for comparisons to the character.

(astronomy, obsolete, informal) Eris (dwarf planet)


Perseus

Latin from the Ancient Greek Περσεύς (Perseús).

(astronomy) An autumn constellation of the northern sky, said to resemble the mythical hero. It includes the stars Algenib, Algol, and Mirfak.


ingress

en-noun

ingress (countable and uncountable, plural ingresses)

From Latin ingressus, from the verb ingredior.

(astronomy) The entrance of the Moon into the shadow of the Earth in eclipses, or the Sun's entrance into a sign, etc.


albedo

albedo (countable and uncountable, plural albedos or albedoes)

Borrowed from Latin albēdō (“whiteness”).

bor+

For track, painting rails white at weak points that are more prone to buckling (where the 'critical rail temperature' is close to the 'stress free temperature' [...]) increases their albedo and can help slow how quickly they heat up, reducing their temperature by perhaps five degrees or so.

2022 August 10, Gareth Dennis, “How can we run trains when the heat is on?”, in RAIL, number 963, page 45:

(physics, meteorology, astronomy, optics) The fraction of incident light or radiation reflected by a surface or body, commonly expressed as a percentage.


Cupid

From Latin Cupīdō, personification of cupīdō (“desire, desire of love”), from cupidus (“eager, greedy, passionate”), from cupere (“to desire”).

Cupid is so small and far away that it can only be seen with the Hubble Space Telescope.


terminator

[ˈtɜː.mɪ.næɪ.ɾə]

* Partly from post-classical Latin terminator (5th century), from Latin terminō; partly from terminate + -or.
* (android that kills humans): After the 1984 film The Terminator.

Harriot, looking at the moon, saw the irregular terminator, the highlights and shadows, the mountain ranges and valleys that Galileo had described – and he also convinced himself that he saw Galileo's imaginary crater.

2015, David Wootton, The Invention of Science, Penguin, published 2016, page 218:

(astronomy) The line between the day side and the night side of a moon, planet or other celestial body.

терминатор

the line between the day side and the night side


Goldilocks planet

en-noun

Goldilocks planet (plural Goldilocks planets)

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From the children's story Goldilocks, in which one of the bowls of porridge the protagonist tries is neither too hot nor too cold, but just right.

(astronomy) A planet which orbits in the habitable zone around a star, where temperatures like those on Earth occur, allowing for the possible existence of liquid water and of life.

kultakutriplaneetta

planet with possible existence of liquid water and of life


Milky Way

LL-Q1860 (eng)-Flame, not lame-Milky Way.wav

From Middle English Milky Wey, a calque of Latin Via Lactea (literally “milky road”), a calque of Ancient Greek γαλαξίας (galaxías), referring to its appearance as a pale band of stars across the sky. Compare also Old English Īringes weġ (“Milky Way”), Old Norse Mjólkrhringr (“Milky Way”, literally “milk-ring, milk-circle”). The reference to the galaxy is an extension of the second sense.

cog

Meronyms: Galactic Center, Sagittarius A*

This whole earth which we inhabit is but a point in space. How far apart, think you, dwell the two most distant inhabitants of yonder star, the breadth of whose disk cannot be appreciated by our instruments? Why should I feel lonely? is not our planet in the Milky Way?

1854 August 9, Henry D[avid] Thoreau, “Solitude”, in Walden; or, Life in the Woods, Boston, Mass.: Ticknor and Fields, →OCLC, page 144:

From a cosmic perspective, even our host galaxy, the Milky Way, is not particularly special[…]

2021, William Sheehan, Jim Bell, chapter 13, in Discovering Mars, page 294:

(astronomy) The Milky Way Galaxy, the galaxy in which Earth is located.

དགུ་ཚིགས་སྐྱ་མོ (dgu tshigs skya mo, literally “pale galaxy”)

གཟའི་མུ་ཁྱུད (gza'i mu khyud, literally “fence of the planet”)

[…] a random shower of amber lights—a spray of golden sparks that […] glinted softly upon the sea of dark foliage like the pallid stars of the milky-way.

1869, Mark Twain, chapter XXXII, in The Innocents Abroad, page 348:

(astronomy) A broad band of diffuse white light, visible in the night sky; our view of the dense portions of the Milky Way Galaxy from inside the galaxy.


Big Bang

Coined by English astronomer Fred Hoyle on the BBC Third Programme, broadcast at 18:30 GMT on 28 March 1949. It is a popular but misinformed belief that this was intended as a derogatory term, Hoyle being a proponent of the opposing steady state theory, but Hoyle himself has rejected that notion.

On scientific grounds this big bang assumption is much less the palatable of the two.

1955, Fred Hoyle, chapter 6, in The nature of the universe, page 113:

(cosmology) The cosmic event that marks the beginning of time and the rapid expansion of space for the visible universe. The evolution of the universe since that beginning point is described by the Big Bang Theory.


winter solstice

en-noun

winter solstice (usually uncountable, plural winter solstices)

(astronomy) The moment when the Earth is in that point of its orbit where the northern or southern hemisphere is most inclined away from the sun.

зимно слънцестоене

the moment when the hemisphere is most inclined away from the sun


summer solstice

summer solstice (usually uncountable, plural summer solstices)

(astronomy) The moment when the Earth is in that point of its orbit where the northern or southern hemisphere is most inclined toward the sun.

الإنقِلَاب الصّيفِيّ

the moment when the hemisphere is most inclined toward the sun


Thalia

From Ancient Greek Θαλία (Thalía) or Θάλεια (Tháleia); from Ancient Greek θάλλω (thállō, “flourish, to be verdant”).

uder

(astronomy) 23 Thalia, a main belt asteroid.


halo

From Latin halōs, from Ancient Greek ἅλως (hálōs, “threshing floor; disk; disk of the sun or moon; ring of light around the sun or moon”), of unknown origin. The threshing floor's circular threshold or oxen walking on it in a circle gave rise to the other meanings. Used in English since 1563; the sense of light around someone’s head since 1646.

der

massive astronomical compact halo object

massive astrophysical compact halo object

(astronomy) A cloud of gas and other matter surrounding and captured by the gravitational field of a large diffuse astronomical object, such as a galaxy or cluster of galaxies.


radiant

From Middle English radyant, from Latin radiāns, radiantis, present participle of radiāre (“to emit rays or beams”).

(astronomy) The apparent origin, in the night sky, of a meteor shower.


siren

From Middle English siren, from Old French sereine and Latin Sīrēn, Sīrēna, from Ancient Greek Σειρήν (Seirḗn). The mammalian sense was first attested in French in Dominique Bouhours, Les entretiens d'Ariste et d'Eugène, in 1671. The aquatic salamander sense was originally introduced by Linnaeus in 1766, for a genus of his reptiles. Doublet of serin.

2017, B.P. Abbott, “A gravitational-wave standard siren measurement of the Hubble constant”, in (Please provide the book title or journal name):

(astronomy, astrophysics) An astrophysical event that can be used for calculating cosmic distances.


pixie

Uncertain; 17thC, originally in the folklore of southwest England; perhaps diminutive of Swedish pysk (“fairy”); perhaps Puck + -sy; see Wikipedia.

(astronomy, meteorology) An upper-atmospheric optical phenomenon associated with thunderstorms, a short-lasting pinpoint of light on the surface of convective domes that produces a gnome.


apocatastasis

From Latin, from Ancient Greek ἀποκατάστασις (apokatástasis, “restoration, reëstablishment”), from ἀποκαθίστημι (apokathístēmi, “to stand up again”), from ἀπό- (apó-, “back again”) + καθίστημι (kathístēmi, “I set, place, constitute, appoint”), from κατά- (katá-, “down, for”) + ἵστημι (hístēmi, “I set, stand, establish”).

uder

ἀποκατάστασις

The accurate apocatastasis (i.e. regression to the same sign) of the moon, and in a similar manner of the sun.

1822, Apuleius, translated by Thomas Taylor, Metamorphosis, or Golden Ass, I 33:

(rare) Restoration, renovation, reestablishment, particularly:

(astronomy) Return to the same apparent position, as after a revolution.


tessera

Borrowed from Latin tessera (“a cube, a die with numbers on all six sides”), from Ancient Greek τέσσαρες (téssares, “four”).

uder

(planetology) complex-ridged surface feature seen on plateau highlands of Venus and perhaps on Triton


astration

(physics, astronomy) In the galactic cycle of matter, the incorporation of matter into a stellar interior during star formation, especially when referring to a specific element or isotope.


Eris

Borrowed from Ancient Greek Ἔρις (Éris), from ἔρις (éris, “strife”).
See also Eris (mythology) on Wikipedia.Wikipedia and Eris (dwarf planet) on Wikipedia.Wikipedia

pedia

Today, Xena is no longer Xena but has been officially renamed Eris, after the Greek goddess of strife and discord—which hints at the climate in planetary science at the time. Its moon has a similarly appropriate name, Dysnomia (lawlessness) in Greek mythology, the daughter of Eris. Observations of Eris and Dysnomia have confirmed that Eris is 27 per cent more massive than Pluto, though of a similar diameter.

2013, Fred Watson, Star-Craving Mad: Tales from a Travelling Astronomer, Allen & Unwin, page 35:

(astronomy) The celestial body 136199 Eris, the most-massive known dwarf planet in the Solar System and the largest known object in the scattered disk; formerly nicknamed Xena.

136199 Eris (2003 UB313)

See Provisional designation in astronomy on Wikipedia.


Metis

From Ancient Greek Μῆτις (Mêtis) from Ancient Greek μῆτις (mêtis, “wisdom”).

(astronomy) 9 Metis, a main belt asteroid.


longitude

en-noun

longitude (countable and uncountable, plural longitudes)

From Middle English, borrowed from Old French longitude, from Latin longitūdō (“length, a measured length”), from longus (“long”).

der

(geography, astronomy) Any imaginary line perpendicular to the equator and part of a great circle passing through the North Pole and South Pole.

llonxitú

imaginary line through North Pole and South Pole


stellar

en-adj

stellar (comparative more stellar, superlative most stellar)

more stellar (comparative)
most stellar (superlative)

(astronomy, not comparable) Of, pertaining to, or characteristic of stars.

yjor

of, pertaining to, or characteristic of stars


meridian

The noun is derived from Late Middle English meridian, meridien (“midday, noon; position of the sun at noon; the south; longitude of a place; (astronomy) celestial meridian”) [and other forms], from Anglo-Norman meridien (“midday”), Middle French meridien (“midday; the south; terrestrial meridian; (astronomy) celestial meridian”) (modern French méridien), and Old French meridiane, meridiiene, and from their etymon Latin merīdiānum (“midday; position of the sun at noon; the south”), a noun use of the neuter form of merīdiānus (“relating to midday; southern”); see further at etymology 1.
Sense 1.1 (“celestial meridian”) is ultimately modelled after Latin merīdiāna līnea (“meridian line”). Sense 5.2 (“midday rest; siesta”) is modelled after Late Latin meridiana (“midday; midday rest”), probably short for Latin merīdiāna hōra (“midday time”).
The verb is derived from the noun.

nb...

meridene, meridiane, meridien, meridyan, meridyen, merydien, merydyen,

cog

In full celestial meridian: a great circle passing through the poles of the celestial sphere and the zenith for a particular point on the Earth's surface.

meridiano

great circle passing through the poles of the celestial sphere and the zenith for a particular point on the Earth’s surface

In this Place of Venus the Hour and Amplitude of the Sun's Riſing, for one Half of the Year, are the ſame with thoſe of his Setting in the other Half; which will alſo happen in all Places under the firſt Meridian, where he riſes and ſets: […]

1746 March 31 (Gregorian calendar), James Ferguson, “VI. The Phænomena of Venus, Represented in an Orrery Made by James Ferguson, Agreeable to the Observations of Seignior Bianchini.”, in Philosophical Transactions. Giving Some Account of the Present Undertakings, Studies, and Labours, of the Ingenious, in Many Considerable Parts of the World, volume XLIV, number 479, London: […] T. Woodward, […] ; and C. Davis […] printers to the Royal Society, →DOI, →OCLC, paragraph 15, page 140:

Thought he, it’s a wicked world in all meridians; I’ll die a pagan.

1851 November 14, Herman Melville, “Biographical”, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, →OCLC, page 62:

(also geography) In full terrestrial meridian: a great circle on the Earth's surface, passing through the geographic poles (the terrestrial North Pole and South Pole); also, half of such a circle extending from pole to pole, all points of which have the same longitude.

خَطّ الطُّول

great circle on the Earth’s surface, passing through the geographic poles


Irene

Borrowed from French Irène, from Ancient Greek Εἰρήνη (Eirḗnē, “peace”), name of a goddess of peace, of early Christian saints, and of an 8th-century Byzantine empress. Doublet of Eirini.

(astronomy) 14 Irene, a main belt asteroid.


Aldebaran

From Arabic اَلدَّبَرَان (ad-dabarān, “the follower”), named so because it follows the Pleiades.

der

اَلدَّبَرَان

The kingly brilliancy of Sirius pierced the eye with a steely glitter, the star called Capella was yellow, Aldebaran and Betelgueux shone with a fiery red.

1874, Thomas Hardy, Far from the Madding Crowd:

The brightest object depicted is Jupiter which stands near the red giant star Aldebaran in Taurus.

2012 December 9, Alan Pickup, The Guardian:

(astronomy) One of the brightest stars in the sky, now recognised to be a binary star in the constellation Taurus (alpha (α) Tauri); an orange giant, 68 light years from Earth.


transit

en-noun

transit (countable and uncountable, plural transits)

From French, from Latin transire (“to go across, pass in, pass through”), from trans (“over”) + ire (“to go”).

der

(astronomy) The passage of a celestial body or other object across the observer's meridian, or across the disk of a larger celestial body.


transit

en-verb

transit (third-person singular simple present transits, present participle transiting, simple past and past participle transited)

transits (present singular third-person)
transiting (participle present)
transited (participle past)
transited (past)

(astronomy, intransitive) To make a transit.


axis of evil

2002 State of the Union Address
George W. Bush
axis of evil

Coined by American political commentator David Frum in 2002 and first used publicly by President George W. Bush in the 2002 State of the Union Address. Possibly from a historical analogy to the German-Italian-Japanese axis. Extended to astrophysics by Portuguese scientist João Magueijo in 2005.

coin

cosmic microwave background
cosmic microwave background

(astrophysics, cosmology) An anomaly in the temperature of the cosmic microwave background as the result of a preferential axis which may have shaped the development of the universe, sometimes abbreviated AOE.


intergalactic

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Men In Black 3 finagles its way out of this predicament by literally resetting the clock with a time-travel premise that makes Will Smith both a contemporary intergalactic cop in the late 1960s and a stranger to Josh Brolin, who plays the younger version of Smith’s stone-faced future partner, Tommy Lee Jones.

2012 May 24, Nathan Rabin, “Film: Reviews: Men In Black 3”, in The Onion AV Club:


galactic

en-adj

galactic (comparative more galactic, superlative most galactic)

more galactic (comparative)
most galactic (superlative)

Borrowed from Ancient Greek γαλακτικός (galaktikós, “milky”), from γάλα (gála, “milk”). Doublet of galactico.

bor

Galactic astronomy is the study of the Milky Way.

(astronomy, specifically, sometimes capitalized) Relating to the Milky Way galaxy.

Relating to a galaxy.
Relating to the Milky Way galaxy.


PMS

(astronomy, of a star) Initialism of pre-main sequence.


helioscope

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(astronomy) An apparatus for viewing the Sun without harming the eye, by means of an optical filter that attenuates most of sunlight while allowing only a small amount of the solar radiation.


Belinda

Alexander Pope
Belinda
Belinda (moon)
The Rape of the Lock

From Belle + -inda, base from various Romance sources such as French belle, Italian bella (“beautiful”), suffix Latinate form of German linde (“soft”) (English linden, lithe). Popularised by Alexander Pope in his poem The Rape of the Lock (1714). The moon is named after a character in Pope's poem.

This moon's orbit is nearly identical to that of Belinda, about 47,000 miles (75,000 km) from Uranus.

2006, Linda T. Elkins-Tanton, Uranus, Neptune, Pluto, and the Outer Solar System, page 52:

It belongs to the Portia group, made up of Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Cupid, Belinda and Perdita; these satellites have similar orbits and photometric characteristics.

2011, Patrick Moore, Robin Rees, editors, Patrick Moore's Data Book of Astronomy, page 230:

Miranda and the more recent discoveries have also been named after Shakespearean characters, with the exception of Belinda (1986 U5), which was named after a character from Pope's “The Rape of the Lock.”

2012, Peter Bond, Exploring the Solar System, page 297:

(astronomy) The ninth satellite of Uranus.


Oort Cloud

Named after Dutch astronomer Jan Hendrik Oort.

(astronomy) The Solar System's Oort cloud, extending from 50,000 to 100,000 astronomical units (approximately 1 light year) from the sun; supposedly the source of most comets around the Solar System.


ecliptic

Borrowed from Latin eclīptica. So named because an eclipse can occur only when the Moon lies on this plane.

(astronomy) The great circle on the celestial sphere that is the mean apparent path of the sun as viewed from the earth.

(astronomy) The plane in which this great circle lies.


WIMP

en-noun

WIMP (countable and uncountable, plural WIMPs)

weakly interacting massive particle#English

(astronomy, physics) Acronym of weakly interacting massive particle.


weakly interacting massive particle

weakly interacting massive particle (plural weakly interacting massive particles)

weakly interacting massive particles (plural)

(astronomy, physics) A hypothetical class of particle, proposed to explain the dark matter problem.

robust associations of massive baryonic objects


Francisco

en-proper noun

Francisco (countable and uncountable, plural Franciscos)

From Latin Franciscus. Doublet of Francis.
* (given name): From Romance Francisco (Portuguese Francisco, Spanish Francisco)
* (moon of Uranus): From the naming pattern established for moons of Uranus, being references to the works of William Shakespeare. From being a character in the play The Tempest

(astronomy) A moon in Uranus, Solar System


Prometheus

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From Ancient Greek Προμηθεύς (Promētheús), from πρό (pró, “before”) + μανθάνω (manthánō, “to think”).

(astronomy) A moon of the planet Saturn.


iceteroid

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keyhole

gravitational keyhole
gravitational keyhole


nova remnant

(astronomy) The ejected material left behind by novae.


multiverse

First appears c. 1895. Blend of multiple + universe, coined by American philosopher William James. By surface analysis, multi- + -verse.

coined

Meronyms: monoverse, parallel universe

Our universe is a very small part of the multiverse.

And, it must be remembered, that in the great multiverse they were a mere scattering of seeds; seeds that must survive many elements if they were to grow.

1963 May, Michael Moorcock, “The Blood Red Game”, in Science Fiction Adventures, volume 6, number 32, London: Nova Publications:

I have been describing show us that the multiverse exists and that it contains many counterparts of each particle in the tangible universe. To reach the further conclusion that the multiverse is roughly partitioned into parallel universes, we must consider interference phenomena involving more than one tangible particle.

1998 [1997], David Deutsch, The Fabric of Reality, New York: Penguin Books, →ISBN, page 46:

I can’t help feeling that in the closest arm of the multiverse, there is a version of me that is fatter and happier.

2020, Raven Leilani, Luster, Picador, published 2021, page 26:

(physics, cosmology) The hypothetical group of all the possible universes in existence.

كون متعدد

hypothetical group of all possible universes


conjunctive

From Latin coniunctivus (“serving to connect”), from coniunctus, past participle of coniungere; compare conjoin. From late 15th c; grammatical sense from 1660s.

uder

(astrology, astronomy) Relating to a conjunction (appearance in the sky of two astronomical objects with the same right ascension or the same ecliptic longitude).


astronomical

en-adj

astronomical (comparative more astronomical, superlative most astronomical)

more astronomical (comparative)
most astronomical (superlative)

Attested since at least 1550, from Middle French astronomique or directly from Latin astronomicus, from Ancient Greek ἀστρονομικός (astronomikós).

uder

ἀστρονομικός

Finally, all men saw that astronomical knowledge lied not, and they awaited the comet.

1839, Edgar Allan Poe, The Conversation of Eiros and Charmion:

Drawings and pictures are more than mere ornaments in scientific discourse. Blackboard sketches, geological maps, diagrams of molecular structure, astronomical photographs, MRI images, the many varieties of statistical charts and graphs: These pictorial devices are indispensable tools for presenting evidence, for explaining a theory, for telling a story.

2012 March 24, Brian Hayes, “Pixels or Perish”, in American Scientist, volume 100, number 2, archived from the original on 2013-02-19, page 106:

(not comparable, astronomy) Of or relating to astronomy.


Terpsichore

From Ancient Greek Τερψιχόρη (Terpsikhórē, from τέρψις (térpsis, “enjoyment, delight”) + χορός (khorós, “chorus”)).

uder

(astronomy) 81 Terpsichore, a main belt asteroid.


Thetis

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(astronomy) 17 Thetis, one of the main belt asteroids.


plume

From Late Middle English plum, plume (“feather; plumage”), from Anglo-Norman plum, plume f and Middle French, Old French plume f, plome (“plumage; down used for stuffing pillows, etc.; pen, quill”) (modern French plume f (“feather; pen, quill; pen nib; (figurative) writer”)), and directly from its etymon Latin plūma f (“feather; plumage; down”) (compare Late Latin plūma f (“pen, quill”)), from Proto-Italic *plouksmā, ultimately from Proto-Indo-European *plewk- (“to fly; to flow; to run; to flap with hands; to splash”).
The English word is a doublet of pluma.

der

(astronomy) An arc of glowing material (chiefly gases) erupting from the surface of a star.

panache

arc of glowing material erupting from the surface of a star


firmament

en-noun

firmament (countable and uncountable, plural firmaments)

From Middle English firmament, furmament (“heaven; sky”), from Old French firmament (“firmament”), or from its etymon Latin firmāmentum (“support; sky”), from
firmāre (“to strengthen”) + -mentum (suffix indicating an instrument or medium, or the result of an action). Firmāre is the present active infinitive of firmō (“to make firm, strengthen”), from firmus (“firm, strong, stable”), ultimately from Proto-Indo-European *dʰer- (“to hold; to support”).
The Latin word was used in the Vulgate version of the Bible to translate the
Ancient Greek στερέωμα (steréōma, “foundation, framework; firmament”) in the Septuagint (Greek Old Testament), which in turn was used to translate the Hebrew רָקִיעַ (rāqī́aʿ, “celestial dome, vault of heaven”), from the root ר־ק־ע (r-q-`); in Classical Syriac the similar root ܪ ܩ ܥ (related to compacting) gave rise to ܪܩܝܥܐ (rəqīʿā, “compact; firm; firmament, heavens, sky; celestial sphere”).

ref

From Petrus Apianus, Gemma Frisius (1539) Petri Apiani cosmographia, per Gemmam Phrysium, apud Louanienses medicum ac mathematicum insignem, restituta: additis de adem re ipsius Gemmae Phry. libellis, ut sequens pagina docet, Antwerp: In pingui gallina Arnoldo Berckma[n]no [Arnold Birckmann], →OCLC.

ሰማይ

vault of the heavens — see also heavens, sky

ala

field or sphere of an activity or interest — see also field, sphere

[B]etweene the ſphere of Saturne and the Firmament, there is ſuch an incredible and vaſt ſpace or diſtance (7000000. ſemidiameters of the earth, as Tycho [Brahe] calculates) void of ſtarres: [...]

1638, Democritus Junior [pseudonym; Robert Burton], “Ayre Rectified. With a Digression of the Ayre.”, in The Anatomy of Melancholy. […], 5th edition, Oxford, Oxfordshire: […] [Robert Young, Miles Flesher, and Leonard Lichfield and William Turner] for Henry Cripps, →OCLC, partition 2, section 2, member 3, page 254:

But if we yet rise higher, and consider the fixed stars as so many vast oceans of flame, that are each of them attended with a different set of planets, and still discover new firmaments and new lights, that are sunk farther in those unfathomable depths of ether, so as not to be seen by the strongest of our telescopes, we are lost in such a labyrinth of suns and worlds, and confounded with the immensity and magnificence of nature.

1712 July 13 (Gregorian calendar), [Joseph Addison], “WEDNESDAY, July 2, 1712. Paper X. On the Pleasures of the Imagination.”, in The Spectator, number 420; republished in Alexander Chalmers, editor, The Spectator; a New Edition, […], volume IV, New York, N.Y.: D[aniel] Appleton & Company, 1853, →OCLC, page 79:

The World Cœlestial. Containing 11 Sphæres or Heavens, ſay the Theologians and Aſtronomers. [...] Theſe are called the Primum Mobile, the Chriſtaline Heaven, the Firmament adorned with the Fixed Stars, and the Heavens of the Seven Planets.

1715, H[enry] Curson, “A Cosmographical Introduction to the Geographical Description of the World”, in A New Description of the World. […], 2nd edition, […] Benj[amin] Barker, […], →OCLC:

(uncountable, astronomy, historical) In the geocentric Ptolemaic system, the eighth celestial sphere which carried the fixed stars; (countable, by extension) any celestial sphere.


cluster

→ Catalan: clúster

→ French: cluster

→ German: Cluster

→ Italian: cluster

→ Japanese: クラスター (kurasutā)

→ Portuguese: cluster

→ Russian: кла́стер (kláster)

→ Spanish: clúster, cluster

→ Swedish: kluster

High Performance Computing Center, Stuttgart

The noun is derived from Middle English cluster (“bunch, cluster, spray; compact body or mass, ball”) [and other forms], from Old English cluster, clyster (“cluster, bunch, branch”), from Proto-Germanic *klas-, *klus- (“to clump, lump together”) (possibly from Proto-Indo-European *gel- (“to ball up; to clench; to amass”)) + *-þrą (suffix forming nouns denoting an instrument or tool). The English word is probably a doublet of clot.
The verb is derived from the noun.
Cognates
* Dutch klister (“cluster”) (dialectal)
* Icelandic klasi (“cluster; bunch of grapes”)
* Low German Kluuster (“cluster”)
* Swedish kluster (“cluster”)

nb...

closter, clostre, clouster, clowster, clustre, clustyr

բույլ

(of galaxies):

(of stars):

The Pleiades cluster contains seven bright stars.

My fellow biotic: You have been selected to receive this transmission because of our shared plight. Few understand us, fewer tolerate us. We must stand together. We must build our own new world. Come. Join us in the Hawking Eta cluster. Only as one body can we right the wrongs done to our kind.

2008, BioWare, Mass Effect, Redwood City, Calif.: BioWare/Electronic Arts, →ISBN, PC, scene: Citadel:

A bunch or group of several discrete items that are close to each other.

(astronomy) A group of galaxies, nebulae, or stars that appear to the naked eye to be near each other.


periodic

/ˌpɪɹiˈɒdɪk/

/ˌpɪɹiˈɑdɪk/

From French périodique, from Medieval Latin periodicus (“cyclical”), from Latin periodus (“complete sentence, period, circuit”), from Ancient Greek περίοδος (períodos, “cycle, period of time”). By surface analysis, period + -ic.

der

(astronomy) Pertaining to the revolution of a celestial object in its orbit.

jaksollinen

(astronomy) pertaining to the revolution of a celestial object in its orbit


rolling stone

From the proverb a rolling stone gathers no moss.


salve

en-verb

salve (third-person singular simple present salves, present participle salving, simple past and past participle salved)

salves (present singular third-person)
salving (participle present)
salved (participle past)
salved (past)

(obsolete, astronomy) To save (the appearances or the phenomena); to explain (a celestial phenomenon); to account for (the apparent motions of the celestial bodies).


planetoid

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The group of small bodies that circle round the Sun, outside the orbit of Mars, are known under the designation of the planetoids.

1856, Robert James Mann, A guide to astromomical science, page 231:

Numbering of the Planetoids or Asteroidal Planets.—In numbering the planetoids a difficulty has arisen [...]

1859, J.D. & E.S. Dana, The American journal of science, page 153:

1979, Tsunami generation by pelagic planetoid impact:

if one can argue for the early existence of a few largely molten planetoids with dimension of kilometers or tens of kilometers, one can quite as easily argue for very large numbers of such planetoids.

1979, H.A. Zook, “On a New Model for the Generation of Chondrites”, in Lunar and Planetary Science, volume xii, page 1242:

(astronomy, dated) An asteroid of any size

(astronomy, dated) An asteroid-like body in an orbit beyond the asteroid belt, such as a centaur or Kuiper belt object

1991, Optimal trajectories for an ion driven spacecraft from earth to the planetoid Vesta:

After discovering "planetoids", bodies orbiting the Sun, even larger than Pluto's moon Charon ... the question of how Sedna and other planetoids came to be.

2009, Paul A. Czysz, Claudio Bruno, Future Spacecraft Propulsion Systems, pages 377–378:

Eris [...] was the upstart planetoid that knocked Pluto off the planetary lists

2009, Patricia Daniels, Robert Burnham, The New Solar System: Ice Worlds, Moons, and Planets Redefined, National Geographic Books, page 173:

(astronomy) A larger, planetary, body in orbit around the Sun, such as Vesta or (candidate) dwarf planets such Eris or Sedna

Plate tectonics is a style of convection for an active planetoid where lid fragment (plate) motions reflect sinking of dense lithosphere in subduction zones […] In 2015 humanity completed a 50+ year effort to survey the 30 largest planets, asteroids, satellites, and inner Kuiper Belt objects, which we informally call “planetoids”.

2018 January 24, Stern, Gerya & Tackley, “Stagnant lid tectonics: Perspectives from silicate planets, dwarf planets, large moons, and large asteroids”, in Geoscience Frontiers, volume 9, number 1, pages 103-119:

planetary-mass object
planetary-mass object

(astronomy) Any planetary body, including classical planets and moons: a planetary-mass object

We prefer the word "planetoid" as a new word to describe round objects orbiting the sun.

2006, Mike Brown, “Sedna”, in (Please provide the book title or journal name):

A dwarf planet or a planetoid is a celestial body that [...]

2007, Hannu Karttunen et al., editors, Fundamental Astronomy, 5th edition, page 131:

'Dwarf planet' is a dumb phrase. For years we've called things like Pluto and Xena 'planetoids'—planetlike.

2010, Mike Brown, How I Killed Pluto and Why It Had It Coming, page 223:


plage

From French plage, from Late Latin plagia, from Latin plaga (“region”) (cognate with English flake). Doublet of playa.

(astronomy) A bright region in the chromosphere of the Sun.


Metonic cycle

According to the Metonic cycle, a lunar calendar begins on the same solar date every 19 years.

(astronomy, calendar studies) A particular approximate common multiple of the tropical year and the synodic month; in other words, the 19-year period over which the lunar phases occur on the same dates.


Margaret

en-proper noun

Margaret (countable and uncountable, plural Margarets)

From the name of a legendary third century saint, from Middle English Margaret, from Old French Margaret (French Marguerite), from Latin Margarita, from Ancient Greek μαργαρίτης (margarítēs, “pearl”), ultimately from an Indo-Iranian source.
The same source, through folk etymology, has produced Old English meregrot (“pearl”, literally “stone or pebble of the sea”), related to Old Saxon merigrita, merigriota (“pearl”), Old High German merigrioz, equivalent to mer- + groat.

cog

Astronomers discovered nine small moons lying outside the orbit of Oberon (Francisco, Caliban, Stephano, Trinculo, Sycorax, Margaret, Prospero, Setebos, and Ferdinand) between 1997 and 2003.

2009, Richard Schmude, Jr., Uranus, Neptune, and Pluto and How to Observe Them, page 58:

The odd one out is Margaret, which travels in a "normal" prograde direction, though it has the most eccentric orbit of all the Uranian satellites.

2012, Peter Bond, Exploring the Solar System, page 297:

[…]moons known to be moving in a prograde or direct orbit is Margaret, orbiting Uranus at an average distance of nearly nine million miles (14,845,000 km) in an orbit that currently exceeds all other Solar System moons in terms of eccentricity (0.7979).[…]Margaret takes about 4.6 Earth years to complete a single orbit of the planet.

2013, David A. J. Seargent, Weird Worlds: Bizarre Bodies of the Solar System and Beyond, page 225:

(astronomy) A moon of Uranus, named for a character in Much Ado About Nothing.


latitude

en-noun

latitude (countable and uncountable, plural latitudes)

Borrowed into Middle English from Old French latitude, from Latin lātitūdō (“breadth, width, latitude”), from lātus (“broad, wide”), from older stlātus.

der

Coordinate term: longitude

The oat is hardier than wheat, and ripens in higher latitudes.

1880, Arthur Herbert Church, Food: Some Account of Its Sources, Constituents and Uses, London: Chapman and Hall, page 72:

Far from the center of Shang civilization, Wu-ch'eng is located well south of the Yangtze at approximately the same latitude as Ch'ang-sha in the west and Wen-chou in the east.

2011, Ralph D. Sawyer, Ancient Chinese Warfare, Basic Books, →ISBN, →LCCN, →OCLC, →OL, page 137:

(geography, astronomy, countable) The angular distance north or south from a planet's equator, measured along the meridian of that particular point.

خَطّ عَرْض

angular distance north or south from the equator

(astronomy) The angular distance of a heavenly body from the ecliptic.


heliocentrism

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Shortened from heliocentricism, from heliocentric + -ism, from Ancient Greek ἥλῐος (hḗlĭos, “sun”) + κέντρον (kéntron, “centre”), equivalent to helio- + -centrism.

1923, Felix Adler, "The Reconstruction of the Spiritual Ideal," American Ethical Union, 68.
Geocentrism has been displaced by heliocentrism. Heliocentrism, in turn, the claim of the sun, surrounded by its satellites, to a sovereign place in the heavens, has become ridiculous in the face of the wilderness of suns that people the abysses beyond us.

It wasn't until the Renaissance that scientists such as Nicolaus Copernicus and Galileo Galilei showed proof for heliocentrism, or the idea that the planets moved around the sun.

2019, Elizabeth Howell, “PBS Series Takes Astronomy Buffs Back in Time With ‘Ancient Skies’”, in Space.com:

(astronomy, history) The theory that the sun is the center of the universe.

heliosentrisme

the theory that the sun is the center of the universe


Betelgeuse

Ultimately from an alteration of the Arabic يَد الجَوْزَاء (yad al-jawzāʔ, “hand of the central one”), from يَد (yad, “hand”) + جَوْزَاء (jawzāʔ, “central one”).
Jawzā, ‘the central one’, initially referred to Gemini among the Arabs, but at some point they decided to refer to Orion by that name. During the Middle Ages the first character of the name, yā’ (ي, with two underdots), was misread as a bā’ (ب, with one underdot) when transliterating into Latin, thus *Yedalgeuze became Bedalgeuze. This was then misinterpreted during the Renaissance as deriving from a corruption of an original Arabic form إِبْط الجَوْزَاء (ʔibṭ al-jawzāʔ, “armpit of the central one”).

bor

يَد الجَوْزَاء

Even if you don’t know it by name, the red supergiant star Betelgeuse is one of the most familiar sights in the heavens above—a gleaming ruddy dot at the shoulder of the constellation Orion. Although already quite difficult to overlook, Betelgeuse has become even more eye-catching across the past few years because of major changes in its appearance—unexpected fluctuations in its brightness that remain poorly understood.

2023 May 15, Meghan Bartels, “Betelguese’s Brightening Raises Hopes for a Supernova Spectacle”, in Scientific American, archived from the original on 2023-05-15:

(astronomy) A bright-red supergiant intrinsic variable star, the second brightest star in the constellation Orion; Alpha (α) Orionis. It is the tenth brightest star in the nighttime, and one of the largest stars known.


astrometry

en-noun

astrometry (usually uncountable, plural astrometries)

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(astronomy) The branch of astronomy that deals with the measurement of the positions and motions of celestial bodies, particularly stars.


seeing

seeing (countable and uncountable, plural seeings)

(astronomy) The movement or distortion of a telescopic image as a result of turbulence in the Earth's atmosphere.

seeing

the movement or distortion of a telescopic image as a result of turbulence in the Earth's atmosphere


Antoniadi scale

Named for Eugène Michel Antoniadi (1870-1944), who invented it.

(astronomy) a scale of seeing conditions used by amateur astronomers.


Indus

Named by Dutch explorers Pieter Dirkszoon Keyser and Frederick de Houtman between 1595 and 1597. From Latin Indus (“Indian”), commemorating American Indians.

(astronomy) A constellation of the southern sky between Grus and Pavo.


cosmic ray

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(astronomy) An energetic particle originating outside our solar system.

(astronomy) Cosmic radiation: a stream of cosmic rays.


Archaean

From Ancient Greek ἀρχαῖα (arkhaîa, “ancient”), neuter plural of ἀρχαῖος (arkhaîos, “ancient”).

der

(astronomy, "Archean" only) Of or relating to the irregular Jovian moon named for Arche.


hypervelocity

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(astronomy) A velocity greater than escape velocity.


Laplace plane

(mathematics, astronomy) The mean plane occupied by the orbit of a satellite during a precession cycle; the plane normal to the orbital precession pole of the satellite.


precession

en-noun

precession (countable and uncountable, plural precessions)

From Middle English precessioun, precession, from Medieval Latin prēcessiōn-, prēcessio, from Latin praecēdō.

(astronomy, uncountable) The slow gyration of the earth's axis around the pole of the ecliptic, caused mainly by the gravitational torque of the sun and moon.


insulated

en-adj

insulated (comparative more insulated, superlative most insulated)

more insulated (comparative)
most insulated (superlative)

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(astronomy, dated) Situated at so great a distance as to be beyond the effect of gravitation; said of stars supposed to be so far apart that the effect of their mutual attraction is undetectable.


astronomer

From Middle English astronomer, equivalent to astronomy + -er.

(astronomy) One who studies astronomy, the stars or the physical universe; a scientist whose area of research is astronomy or astrophysics


Clotho

From Latin Clōthō, from Ancient Greek Κλωθώ (Klōthṓ), from κλώθω (klṓthō, literally “to spin”).

(astronomy) 97 Klotho, a main belt asteroid.


Epimetheus

From Ancient Greek Ἐπιμηθεύς (Epimētheús, “afterthought, hindsight”).

uder

(astronomy) A moon of the planet Saturn.


Erato

(astronomy) 62 Erato, a main belt asteroid.


Euterpe

(astronomy) 27 Euterpe, a main belt asteroid.


Ganymede

From French Ganymède, from Latin Ganymēdēs, from Ancient Greek Γανυμήδης (Ganumḗdēs, “meant to please”), from γάνυμαι (gánumai, “I rejoice, I am glad”) + μήδεα (mḗdea, “thought, intention”). Doublet of catamite.


Hecate

Via Latin Hecatē from Ancient Greek Ἑκάτη (Hekátē), possibly the feminine equivalent of Ἑκατός (Hekatós) or ἑκάεργος (hekáergos), an obscure epithet of Apollo, variously interpreted as "one who works/operates from afar", "one who drives off", "the far reaching one" or "the far-darter". Some rather suggest that the name derives from Ancient Greek ἑκών (hekṓn, “will”).

(astronomy) 100 Hekate, a main belt asteroid.


Hercules

head

Hercules (plural Herculeses or Hercules or (obsolete) Herculesses or (obsolete) Hercules's)

Herculeses (plural)
Hercules (plural)
Herculesses (obsolete plural)
Hercules's (obsolete plural)

From Latin Herculēs, from Etruscan 𐌇𐌄𐌓𐌂𐌋𐌄 (hercle), from Ancient Greek Ἡρακλῆς (Hēraklês), apparently cognate of Ἥρα (Hḗra, “Hera”) and, according to Haudry, from Proto-Indo-European *yóh₁r̥ (“year, season”) + κλέος (kléos, “glory”).

der

(astronomy) A summer constellation of the northern sky, said to resemble the mythical hero. It lies between the constellations Lyra and Corona Borealis.

(astronomy) A crater in the first quadrant on the moon.


Hermes

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From the Ancient Greek Ἑρμῆς (Hermês), itself of disputed meaning and origin, possibly of non-Indo-European substrate origin or from Proto-Indo-European *ser- (“to bind, put together”).

(astronomy) The planet Mercury when observed as an evening star.


Hestia

From Ancient Greek Ἑστία (Hestía), from ἑστία (hestía, “hearth”).

(astronomy) 46 Hestia, a main belt asteroid.


Vesta

From Middle English Vesta, from Latin Vesta, related to Ancient Greek ἑστία (hestía, “to dwell”) and Ἑστία (Hestía, “Hestia”), all from Proto-Indo-European *h₂wes-; see also Old High German and Old English wesan (“to be”), Gothic wisan, Sanskrit वसति (vasati, “abide dwell”).
Vesta itself came to mean chaste, pure, or virgin, based from this goddess.

cog

(astronomy) The fourth asteroid discovered, and second largest, (4) Vesta.


Melpomene

Borrowed from Ancient Greek Μελπομένη (Melpoménē), from μέλπω (mélpō, “to sing”).


Polyhymnia

Learned borrowing from Ancient Greek Πολυύμνια (Poluúmnia), Πολύμνια (Polúmnia)

lbor

(astronomy) 33 Polyhymnia, a main belt asteroid.


Urania

(astronomy) 30 Urania, a main belt asteroid.


Diana

→ Hawaiian: Kiana
→ English: Kiana

→ Serbo-Croatian: Дајана, Dajana

→ Spanish: Dayana

Borrowed from Late Latin Diāna, short form of Latin Dīāna, derived by syncope from Old Latin Dīvāna, equivalent to dīvus + -āna; roughly akin to Proto-Italic *deiwā (“goddess”) + Proto-Indo-European *-néh₂.
Originally an Old Italic divinity of light and the moon; later identified as the Roman counterpart to Greek goddess Artemis. Cognate of Attic Greek Διώνη (Diṓnē), similarly syncopated from older Ancient Greek Διϝωνη (Diwōnē), whence via Latin Diōne is derived English Dione used in various ways across astronomy, chemistry, biology, and as a given name. From the same root Proto-Indo-European *dyúh₃onh₂- also potentially cognate to English June via Latin Jūnō.

(astronomy) 78 Diana, a main belt asteroid.


Minerva

From Latin Minerva, from Proto-Italic *menezwā, from Proto-Indo-European *menesweh₂, extended from *ménos (“mind”), from *men- (“to think”).

مِينِيرْفَا

goddess of wisdom, especially strategic warfare, and the arts

(astronomy) 93 Minerva, a main belt asteroid.


Andromeda

/ænˈdɹɒmɪdə/

/ænˈdɹɑmɪdə/

Borrowed from Latin Andromeda, itself a borrowing from Ancient Greek Ἀνδρομέδα (Androméda), Ἀνδρομέδη (Andromédē).

(astronomy) A constellation of the northern sky representing the "chained woman" Andromeda in Greek mythology, which is surrounded by the constellations of Cassiopeia, Perseus, and Pegasus, among others.

The Milky Way once had a massive galactic sibling that was shredded and consumed by our closest neighbour, Andromeda, scientists have discovered.

2018 July 23, Hannah Devlin, “Discovered: Milky Way's long-lost galactic sibling”, in The Guardian:

Andromeda is a large, spiral galaxy like the Milky Way. It's between two and three million light years away. On a clear night in a dark place, you can see Andromeda with the naked eye.

2008, Roger Reid, Space (novel), Montgomery, AL: Junebug Books, page 41:

(astronomy) The nearest spiral galaxy to the Milky Way, located within the Andromeda constellation (see Andromeda Galaxy); M31.


circumpolar

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a circumpolar star

(astronomy) Of a celestial body, continually visible above the horizon during the entire 360 degrees of daily travel.


ADT

en-noun

ADT (countable and uncountable, plural ADTs)

(astronomy education) Initialism of astronomy diagnostic test.


equatorial

/ˌɛkwəˈtɔːɹiəl/

(astronomy) A kind of telescope mounted so as to have two axes of motion at right angles to each other, one of them parallel to the axis of the Earth, and each carrying a graduated circle, one for measuring declination, and the other right ascension, or the hour angle, so that the telescope may be directed, even in the daytime, to any star or other object whose right ascension and declination are known.


asterism

From Ancient Greek ἀστερισμός (asterismós, “group of stars”), from ἀστήρ (astḗr, “star”). Analyzable as aster- + -ism.

derived

The Big Dipper, Summer Triangle, and Orion's Belt are asterisms.

Of the constellations, or asterisms. [...] It therefore became necessary to adopt a more general method of distinguishing them. This was accomplished by portioning out the heavens into imaginary figures, of men, birds, fishes, &c. called Constellations or Asterisms.

1825, Geo G. Carey, Astronomy, as it is known at the present day, London, p. 66 f:

Like Pisces and Capricorn, Aquarius is located in that part of the sky known as "Astral Sea," a region inhabited by water asterisms such as Eridanus, Cetus (the Whale), and the Dolphin.

2007, Matilde Battistini, Rosanna M. Giammanco Frongia (translation from Italian into English), Astrology, Magic, and Alchemy in Art, page 60:

(astronomy) An unofficial constellation (small group of stars that forms a visible pattern).


chasm

General American, uncommon, spelling pronunciation

From Latin chasma, from Ancient Greek χάσμα (khásma, “abyss, cleft”).

chasma

long, narrow, steep-sided depression on a body in the solar system

But always and ever there is a yawning chasm below[.]

2019, Li Huang, James Lambert, “Another Arrow for the Quiver: A New Methodology for Multilingual Researchers”, in Journal of Multilingual and Multicultural Development, →DOI, page 1:

(geology, planetology) A deep, steep-sided rift, gap or fissure; a gorge or abyss.


informed

en-adj

informed (comparative more informed, superlative most informed)

more informed (comparative)
most informed (superlative)

From in- + formed; the first sense probably uses in- (“in”), while the second sense uses in- (“prefix of negation”).

the informed stars

(astronomy, obsolete) Not included within the figures of any of the ancient constellations.


solar wind

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(astronomy) The outflow of charged particles from the solar corona into space. Because of the high temperature of the particles of the corona, they are moving at speeds higher than the solar escape velocity.


celestial body

en-noun

celestial body (plural celestial bodies)

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(astronomy, astrology) A natural object which is located outside of Earth's atmosphere, such as a comet, an asteroid, the Moon, a planet, the Sun, or a star.

cos celeste

natural object beyond Earth's atmosphere


companion

From Middle English companion, from Old French compaignon (“companion”) (modern French compagnon), from Late Latin compāniōn- (nominative singular compāniō, whence French copain), from com- + pānis (literally, with + bread), a word first attested in the Frankish Lex Salica as a calque of a Germanic word, probably Frankish *galaibo, *gahlaibō (“messmate”, literally “with-bread”), from Proto-Germanic *gahlaibô. Compare also Old High German galeipo (“messmate”) and Gothic 𐌲𐌰𐌷𐌻𐌰𐌹𐌱𐌰 (gahlaiba, “messmate”); and, for the semantics, compare Old Armenian ընկեր (ənker, “friend”, literally “messmate”). More at co-, loaf. Displaced native Old English ġefēra (literally “fellow traveler”). Doublet of company. Compare mate.

noncog

(astronomy) A celestial object that is associated with another.


seleno-

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seleno- + -centric → selenocentric


selenography

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(astronomy, geography, cartography) The scientific study of the Moon's geographic features; geography of the Moon.


Ferdinand

From Spanish Ferdinando, from Proto-Germanic *fardiz (“journey”) + *nanþaz (“daring”) (from the root of *ninþaną (“to be daring”)).
The moon is named after a character in Shakespeare's The Tempest.


immersion

en-noun

immersion (countable and uncountable, plural immersions)

From late Middle English, borrowed from Late Latin immersiō, immersiōnem (“dipping”).

потапяне

the act of immersing or the condition of being immersed

An occultation of a star by the moon provides two sharply defined observable phenomena: the disappearance of a star behind the disc of the moon (called its immersion), and its subsequent reappearance (or emersion).

2009, Steven Wepster, Between Theory and Observations, Springer Science, →ISBN, page 178:

(astronomy) The disappearance of a celestial body, by passing either behind another, as in the occultation of a star, or into its shadow, as in the eclipse of a satellite.