minimum orbit intersection distance (MOID)
durâ-ye kamine-ye andarsekanj-e madâr
Fr.: distance minimale d'intersection d'une orbite
The minimum distance between the paths of two orbiting objects around a → primary. Such distance between an object and Earth is called Earth MOID.
1) A → quasar of lesser power compared to
ordinary quasars hypothesized to exist at early cosmic times. According to some models,
the Universe was reionized by a population of miniquasars
powered by → intermediate-mass black holes.
Fr.: diagramme de Minkowski
Same as → space-time diagram.
metrik-e Minkofski (#)
Fr.: métrique de Minkowski
The → metric that belongs to a four-dimensional → flat manifold and is given by ds2 = - dt2 + dx2 + dy2 + dz2. Three coordinates represent → space and the fourth coordinate is devoted to → time. The Minkowski metric underlies the → geometry of → special relativity. Compare → Robertson-Walker metric.
In honor of Hermann Minkowski (1864-1909), Russian-born German mathematician, who introduced the concept of the four-dimensional nature of space-time; → metric.
fazâ-zamân-e Minkowski (#)
Fr.: espace-temps de Minkowski
A completely flat four-dimensional space, which contains no gravitating matter, used in the theory of special relativity.
Fr.: objet de Minkowski
A peculiar blue object near the → elliptical galaxy NGC 541 in the → galaxy cluster Abell 194. According to several pieces of evidence, the → starburst in Minkowski's object was triggered by the → radio jet emerging from the → nucleus of the nearby → active galaxy NGC 541. This is similar to the jet-induced → star formation associated with → Centaurus A, and the radio-aligned star forming regions in powerful radio galaxies at → high redshift. Absorption and emission line measurements and broadband → SED fitting, give an age of around 7.5 Myr for Minkowski's object.
Minkowski, R., 1958, PASP, 70, 143; → object.
Lesser or smaller in amount, extent, or size.
From L. minor "lesser, smaller, junior," from PIE base *mei- "small" (cf. L. minuere "make small;" Gk. meion "less," minuthein "to lessen;" Skt. miyate "diminishes, declines;" O.E. minsian "to diminish").
Kehin comparative and superlative of keh "small, little, slender" (related to kâstan, kâhidan "to decrease, lessen, diminish," kam "little, few; deficient, wanting; scarce," (Mid.Pers. kam "little, small, few," O.Pers./Av. kamna- "small, few;" from Mid.Pers. kâhitan, kâstan, kâhênitan "to decrease, diminish, lessen;" Av. kasu- "small, little;" Proto-Iranian *kas- "to be small, diminish, lessen") + -é nuance suffix.
Fr.: petit axe
The axis of an ellipse that is perpendicular to the major axis at a point equidistant from the foci.
Fr.: fusion mineure
The → merging in which one of the galaxies is significantly larger than the other (mass ratios above 10). The larger galaxy will often "swallow" the smaller satellite galaxy. The swallowed galaxy can trigger disk and nuclear star formation or activate a central core with shells that surround the predator.
Fr.: petite planète
An obsolete name used to describe an → asteroid.
Fr.: prémisse mineur
Fr.: terme mineur
For a function f defined on the interval I, the point m such that for each x on I, f(x)≥ m. See also → majorant.
From Fr. minorant, from minorer "to reduce, cut," from L. → minor.
Kehân, from kehidan, from keh "small, little," → minor.
The smaller number, part, or quantity of a whole.
Mintaka (δ Orionis)
The faintest and the westernmost of the three stars which appear in a row and make up the → Orion's Belt. It is a blue star of magnitude 2.23 lying 915 light-years away. Mintaka is in fact an → eclipsing binary with a period of 5.7 days. The main star has a → spectral type of O9.5 and radiates near 90,000 times the → solar luminosity. Mintaka is remarkable as regards the discovery of the → interstellar medium. The ISM was discovered by the German astronomer Johannes Hartmann (1855-1936) through the study of δ Orionis. He remarked that the calcium line at 3934 Å did not share in the periodic displacements of the lines caused by the orbital motion of the star. This suggested that the calcium line was not from the stars but from an intervening interstellar absorbing cloud.
Mintaka, from al-Mintaqah "the belt," from al-Mintaqah al-Jauzâ'
1) (prep.) With the deduction of.
L. minus "less," neuter of minor "smaller," ultimately from PIE *mi-nu-, suffixed form of root *mei- "small;" cf. L. minuere "to diminish, lessen;" Gk. meion "less, smaller;" Av. (+ prefix *ui-) vīmītô.dantānô "with lost teeth;" O.Pers. mīθah- "damage, harm;" Mid.Pers. (+ *ui-) wmys- "to fade;" Mod.Pers. gum, gom "lost;" Ossetian minæg "weak, dim (light)" (Cheung 2007); Skt. miyate "diminishes," Russ. men'she "less;" O.E. minsian "to diminish."
Kaman, from kam "little, few; deficient, wanting; scarce," from Mid.Pers. kam "little, small, few," O.Pers./Av. kamna- "small, few" + suffix -an that occurs in many words, such as rowšan, rowzan "bright, window," anjoman "assembly, association," hâvan "mortar," mihan "homeland, dwelling," barzan "district, neighborhood," rasan "rope." These particular cases are related to Proto-Ir./Av. -ana: raocana-, hanjamana-, hāvana-, maeθana-, *varezana-, and *uraisana- respectively; other cases may have a different origin, e.g. Proto-Ir. *-an.
A unit of angular measurement equal to one sixtieth of a degree.
From O.Fr. minut, from M.L. minuta "minute, short note," from L. minuta, feminin of minutus "small, minute." In M.L., pars minuta prima "first small part" was used by Ptolemy for "one-sixtieth of a circle," later of an hour (next in order was secunda minuta, which became second).
Daqiqé, loan from Ar. daqiqat.
A → red giant → variable star in the constellation → Cetus, called also Omicron (ο) Ceti. Its → visual magnitude varies between 2.0 and 10.1 over a period of about 330 days, and its → spectral type between M5 and M9. Its diameter is 400-500 times that of the Sun, and it lies approximately 420 → light-years away. Mira is a → binary star, consisting of the red giant Mira A along with Mira B. It is the prototype of a class known as → long-period variables, or → Mira variables.
From L. mira "wonderful," as named by J. Hevelius (1611-1687).
Fr.: variables de type Mira
A variant of → Merak.