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

The envelope of wave fronts created by a → supersonic source.

→ Mach number; → wave.

The local → inertial frame and the → inertia of any body results from the distribution of all matter in the Universe. This principle has been neither confirmed nor refuted.

→ Mach number; → number.

1) An apparatus consisting of interrelated parts with separate functions, used in the performance of some kind of work.
2) A device that transmits or modifies force or motion.

From M.Fr. machine "device, contrivance," from L. machina "machine, fabric, device, trick," from Doric Gk. makhana, Attic Gk. mekhane "device, means," related to mekhos "means, expedient," from PIE *maghana- "that which enables," from base *magh- "to be able, have power" (cf. O.C.S. mogo "be able," O.E. mæg "I can").

Mâšin, loanword from Fr.

A collective term for objects that reside in the → halo of a galaxy (in particular → brown dwarfs) and which do not emit enough radiation to be detected from Earth. MACHOs can be spotted using the technique of → microlensing.

Acronym from Massive Astrophysical Compact Halo Objects.

A → Taylor series that is expanded about the reference point zero.

Named after Colin Maclaurin (1698-1746), a Scottish mathematician.

A combining form meaning "large, long, great, excessive," used in the formation of compound words; opposite of → micro-.

From Gk. makros "long, large," from PIE base *mak-/*mek- "long, thin" (cf. L. macer "lean, thin;" O.N. magr, O.E. mæger "lean, thin").

Dorošt "large; rough, fierce," from Mid.Pers. društ "harsh, coarse;" O.Pers. darš- "to dare," daršam (adv.) "mightily;" Av. darš- "to dare," darši-, daršita- "bold, strong;" cf. Skt. dhars- "to be bold, courageous, to attack," dhrsita- "bold, daring;" Gk. thrasys "bold;" O.E. durran; E. dare.

The great world or Universe; the Universe considered as a whole (opposed to → microcosm).
A representation of a smaller unit or entity by a larger one, presumably of a similar structure.

→ macro-; → cosmos.

A stellar → explosion with energies between those of a → nova and a → supernova and observationally distinguished by being brighter than a typical nova (M_V ~ -8 mag) but fainter than a typical supernova (M_V ~ -19 mag) (Kulkarni 2005; arXiv:astro-ph/0510256).

→ macro-; → nova.

Of or relating to scales large enough to be visible to the naked eye or under low order of magnification. Compare → microscopic. → microscopic state.

→ macro-; → -scope + → -ic.

Same as → macrostate.

→ macroscopic; → state.

Statistical physics: A state of a physical system that is described in terms of the system's overall or average properties at a macroscopic level (→ temperature, → pressure, → density, → internal energy, etc.). A macrostate will generally consist of many different → microstates. In defining a macrostate we ignore what is going on at the microscopic (atomic/molecular) level. The → probability of a certain macrostate is determined by how many microstates correspond to this macrostate. Therefore, the greater the number of microstates which lead to a particular macrostate, the greater the probability of observing that macrostate. Same as → macroscopic state. See also → entropy, → Boltzmann's entropy formula, → multiplicity.

→ macro-; → state.

The broadening of a star's → spectral lines due to → Doppler shifts from motions of different parts of the star's atmosphere.

→ macro; → turbulence.

1) Of, relating to, or named from, Ferdinand Magellan (see below).
2) Of or pertaining to characteristic of the → Magellanic Clouds.

Named in honor of Ferdinand Magellan (c. 1480-1521), the Portuguese navigator, who undertook the first voyage around the world. The two Clouds were first described by Magellan's chronicler Pigafetta, after leaving the Strait of Magellan in 1520; → -ic.

A filament of → neutral hydrogen which connects the → Small Magellanic Cloud and → Large Magellanic Cloud. The Magellanic Bridge appears to result from a → close encounter between these two galaxies some 200 million years ago.

→ Magellanic; → bridge.

Two irregular satellite galaxies of our own Galaxy which are visible from the Southern Hemisphere as misty patches in the night sky. → Large Magellanic Cloud; → Small Magellanic Cloud.

→ Magellanic; → cloud.

A class of low-mass galaxies with relatively rare features. In particular, these galaxies are characterized by a → stellar bar whose center is displaced from that of the disk and a one-armed spiral. The → Large Magellanic Cloud (LMC) is considered the prototype of this class of objects. However, despite a wealth of data, there is still a good deal of uncertainty concerning the nature of the LMC's bar. The majority of the observed Magellanic spirals in the nearby Universe share the LMC's structure, in particular the evidence of an offset bar and a one-armed spiral structure. A good example of these systems is NGC 3906, which shows evidence of the bar offset from the photometric center of the galaxy by 1.2 kpc (Pardy et al., 2016, ApJ 827, 149).

→ Magellanic; → spiral; → galaxy.

A thin trail of gas stretching from the → Magellanic System toward our own Galaxy over about 150° on the sky, corresponding to hundreds of thousands of light-years. This gas consists primarily of → neutral hydrogen and is thought to have originated from the Large and Small Magellanic Clouds as a result of tidal interactions with the Milky Way. See, e.g., Fox et al. 2013, arxiv/1304.4240, and references therein.

→ Magellanic; → stream.

A system consisting of the → Magellanic Clouds, the → Magellanic Bridge, and the → Magellanic stream.

→ Magellanic Clouds; → system.

A → metal-poor, → irregular galaxy like the → Large Magellanic Cloud or the → Small Magellanic Cloud. Other examples are: NGC 4449, NGC 4214, and NGC 3109.

→ Magellanic; → type; → galaxy.

1a) The power of apparently influencing events by using mysterious or supernatural forces.
1b) Mysterious tricks, such as making things disappear and reappear, performed as entertainment.
2) Having or apparently having supernatural powers (OxfordDictionaries.com)

M.E. magik(e) "witchcraft," from O.Fr. magique "magic, magical," from L.L. magice "sorcery, magic," from Gk. magike (tekhne "art"), from magos "one of the members of the learned and priestly class," from O.Pers. magu-, possibly from PIE root *magh- "to be able, have power."

Mid.Pers. yâtûk "wizard, sorcerer;" Av. yātu-