Fr.: clair de lune
The light of the Moon.
Mahtâb (Gilaki mângtâb) from mah, mâh (mâng), → moon, + tâb "light," from tâbidan, tâftan "to shine," tafsidan "to become hot" (Av. tāp-, taf- "to warm up, heat," tafsat "became hot," tāpaiieiti "to create warmth;" cf. Skt. tap- "to spoil, injure, damage; to suffer; to heat, be/become hot," tapati "burns;" L. tepere "to be warm," tepidus "warm;" PIE base *tep- "warm").
Fr.: tremblement de lune
A → seismic event occurring on the → Moon; the lunar equivalent of an → earthquake. Moonquakes were first detected by the → seismometers placed on the Moon by Apollo astronauts from 1969 through 1972. The instruments placed by the Apollo 12, 14, 15, and 16 missions were functional until 1977. Unlike earthquakes, moonquakes are not believed to be caused by → tectonic plate movement, but by → tidal forces between Earth and the Moon. There are at least four different kinds of moonquakes: (1) deep moonquakes about 700 km below the surface. They occur at monthly intervals at about 100 distinct sites, indicating that these moonquakes are caused by → stresses from changes in lunar tides as the Moon orbits the Earth; (2) vibrations from the impact of → meteorites; (3) thermal quakes caused by the expansion of the frigid crust when first illuminated by the morning sun after two weeks of deep-freeze lunar night; and (4) shallow moonquakes only 20 or 30 km below the surface (science.nasa.gov/science-news).
barâmad-e mâh (#)
Fr.: lever de la lune
The times at which the apparent upper limb of the ascending Moon is on the astronomical horizon.
forušod-e mâng (#)
Fr.: coucher de la lune
The crossing of the visible horizon by the upper limb of the descending Moon.
lek-e forušod-e mâng
Fr.: retard du coucher de la lune
A unique feature of → Pluto's large satellite → Charon. It appears as a dark reddish area about 475 km in diameter in Charon's north polar region, as revealed in → New Horizons' approach images. It has been proposed that the feature is due to gas from Pluto. A part of Pluto's → atmosphere (→ methane molecules) is transiently cold-trapped and processed at Charon's winter pole (W. M. Grundy et al., 2016, Nature, 14 September).
Fr.: onde de Moreton
A large-scale → shock wave observed in Hα on the Sun's → chromosphere that is generated by the impact of a → solar flare. Moreton waves expand outward at about 1,000 km/s, and may travel for several hundred thousand kilometers. They are accompanied by meter-wave radio bursts.
Named after the American astronomer Gail E. Moreton (1960, A.J. 65, 494); → wave.
radebandi-ye Morgan-Keenan (#)
Fr.: classification de Morgan-Keenan
A system of → spectral classification introduced in 1943 by William W. Morgan (1906-1994), Philip C. Keenan (1908-2000), and Edith M. Kellman (1911-2007) at Yerkes Observatory. Also known as the MK (or MKK) classification or the → Yerkes system.
Named after the two main astronomers, as above; → classification.
The first part or period of the day, extending from dawn, or from midnight, to noon. Not a precise astronomical term.
From M.E. morn, morwen, from O.E. margen earlier morgen (cf. O.H.G. morgen, Goth. maurgins) + → -ing.
Bâmdâd, from Mid.Pers. bâmdâd "morning, dawn," from bâm "beam of light, splendor," bâmik "brilliant" (from Av. *bāma- "light," bāmya- "light, luminous, bright," vīspô.bāma- "all resplendent," from bā- "to shine;" cf. Skt. bhāti- "light, splendor") + dâd "given," from dâdan "to give" (O.Pers./Av. dā- "to give, grant, yield," dadāiti "he gives;" Skt. dadáti "he gives;" Gk. tithenai "to place, put, set," didomi "I give;" L. dare "to give, offer," facere "to do, to make;" Rus. delat' "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do;" PIE base *dhe- "to put, to do").
rujâ (#), setâre-ye bâmdâd (#)
Fr.: étoile du matin
Not actually a star, but the planet Venus shining brightly in the east just before or at sunrise. Opposed to → evening star.
Rujâ "morning star" in Tabari, "star" in Gilaki. This word is a variant of official Pers. ruz "day," since in Tabari and Gilaki the phoneme z is sometimes changed into j, as in rujin = rowzan "window" and jir or jer = zir "under." Therefore it is related to rowšan "bright, clear," rowzan "window, aperture;" foruq "light," afruxtan "to light, kindle;" Mid.Pers. rôšn "light; bright, luminous," rôc "day;" O.Pers. raucah-rocânak "window;" O.Pers. raocah- "light, luminous; daylight;" Av. raocana- "bright, shining, radiant;" akin to Skt. rocaná- "bright, shining," roka- "brightness, light;" Gk. leukos "white, clear;" L. lumen (gen. luminis) "light," from lucere "to shine," related to lux "light," lucidus "clear," luna, "moon;" Fr. lumière "light;" O.E. leoht, leht, from W.Gmc. *leukhtam (cf. O.Fris. liacht, M.Du. lucht, Ger. Licht), from PIE *leuk- "light, brightness;" → morning; → star.
Of or relating to → morphology. Same as morphological
Of or relating to → morphology. Same as morphological
radebandi-ye rixtšenâxti (#)
Fr.: classification morphologique
A classification scheme of galaxies based on their apparent shape. → Hubble classification.
rixt, rixtšenâsi (#)
1) The study of the form or → structure of anything.
From Gk. morphe "form, shape, outward appearance" + → -logy.
Rixt "shape, the way something is cast, as in founding," past stem of rixtan "to cast; to pour; to flow" (Mid.Pers. rēxtan and rēcitan "to flow;" Av. raēk- "to leave, set free; to yield, transfer," infinitive *ricyā; Mod.Pers; rig in morderig "heritage" (literally, "left by the dead"); cf. Skt. rinakti "he leaves," riti- "stream; motion, course;" L. rivus "stream, brook;" Old Church Slavic rēka "river;" Rus. reka "river;" Goth. rinnan "run, flow," rinno "brook;" O.E. ridh "stream." šenâsi, → -logy.
Fr.: relation morphologie-densité
An observationally determined relationship between the → morphological classification of galaxies and the → environments in which they are located. Specifically, the morphology-density relation indicates that early-type galaxies (→ ETG) are preferentially located in high density environments, whereas late-type galaxies (→ LTG) are preferentially found in low density environments. Hence, spiral galaxies are rare in the high densities of clusters and are common in the lower density group environments. Early-type galaxies, on the other hand, are common in clusters and are rarely found in isolation.
A composite image built up from a number of image segments.
From O.Fr. mosaicq "mosaic work," from M.L. musaicum "mosaic work, work of the Muses," from musaicus "of the Muses," from L. Musa.
MOST Space Telescope
teleskop-e fazâyi-ye MOST
Fr.: télescope spatial MOST
A small telescope dedicated entirely to → asterolseismology. MOST is the first space telescope entirely designed and constructed by Canada. It was launched into space in 2003. The satellite weighs only 54 kg and is equipped with an ultra high precision telescope that measures only 15 centimetres in diameter. Despite its tiny size, it is ten times more sensitive than the → Hubble Space Telescope in detecting the minuscule variations in a star's luminosity caused by vibrations that shake its surface. MOST completes one orbit around the Earth every 101 minutes by passing over each of Earth's poles.
MOST, short for Microvariability and Oscillations of STars telescope.
A female → parent.
M.E. mother, moder, O.E. modor; cf. O.S. modar, O.N. moðir, Da. moder, Du. moeder, O.H.G. muoter, Ger. Mutter; PIE *mater- "mother;" akin to Pers. mâdar, as below.
Mâdar, from Mid.Pers. mâd, mâdar; O.Pers./Av. mātar- "mother;" cf. Ossetic mad/madae "mother;" Khotanese mâta "mother;" Skt. mātár- "mother;" Gk. meter, mater; L. mater (Fr. mère, Sp. madre).
The action or process of moving or of changing place or position; movement.
Verbal noun of → move.