Ghost Head Nebula
miq-e sar-e parhib
Fr.: Nébuleuse de la Tête de Fantôme
A star forming region in the → Large Magellanic Cloud, a satellite of our Galaxy, as pictured by the → Hubble Space Telescope. It spans about 50 light-years and contains several young, → massive stars.
Fr.: nébuleuse de la Guitare
A nebula resembling a guitar produced by a → neutron star, which is travelling at a speed of 1600 km per sec! The neutron star leaves behind a "wake" in the → interstellar medium, which just happens to look like a guitar (only at this time, and from our point of view in space). The Guitar Nebula is about 6.5 light years away, in the constellation → Cepheus, and occupies about an arc-minute in the sky, corresponding to about 300 years of travel for the neutron star.
Fr.: nébuleuse de Gum
An immense emission nebula about 40° across lying toward the southern constellations → Vela and → Puppis. It contains the → Vela pulsar and the → Vela supernova remnant, and seems to be created by an outburst of ionizing radiation that accompanied a → supernova explosion.
Named after its discoverer, the Australian astronomer Colin Stanley Gum (1924-1960); → nebula.
Helix Nebula (NGC 7293)
Fr.: Nébuleuse de l'Hélice
A large and bright → planetary nebula in the constellation → Aquarius. Its apparent diameter is about half the size of the full Moon, corresponding to about 2.5 → light-years for a distance of about 700 light-years. It is the nearest bright planetary nebulae to Earth and one of the most spectacular examples of such objects. The Helix Nebula possibly consists of at least two separate disks with outer rings and filaments. The brighter inner disk seems to be expanding at about 100,000 km/h and to have taken about 12,000 years to form. High-resolution observations of the inner edge of the Helix's main ring have revealed thousands of cometary knots of gas with faint tails extending away from the central star. The knots have masses similar to the Earth, but are typically the size of our Solar system. The comet-like shape of the knots results from the steady evaporation of gas from the knots, produced by the strong winds and ultraviolet radiation from the central star of the nebula.The origin of the knots is currently not well understood.
Fr.: nébuleuse de l'Homoncule
A nebula of gas and dust (about 17" x 12" in size), which surrounds the massive star Eta Carinae and lies about 7500 light-years away. The surrounding material was ejected by the massive star in 1843 during its violent eruption, and is now expanding at about 500 km/sec.
Homunculus, "a diminutive human being; little man" (since the nebula resembled a small human to early observers), from L. homin-, homun-, homo "eartly being," humus "the earth" (cf. Pers. zamin "earth, ground," Mid.Pers. zamig "earth;" Av. zam- "the earth;" Skt. ksam; Gk. khthôn, khamai "on the ground;" PIE root *dh(e)ghom "earth") + → -ula, -ule; → nebula.
Miq, → nebula; âdamak "little man."
Horsehead Nebula (NGC 2024)
miq-e sar-e asb, ~ asbsar
Fr.: nébuleuse de la Tête de Cheval
A huge → dark cloud of → interstellar dust that is shaped like a horse's head. It is luminous at its edges because it is in front of the bright → emission nebula IC 434. Its height and width are about 5 and 2.5 → light-years respectively. It is located at a distance of about 1500 light-years in the constellation → Orion. Also known as Barnard 33.
Fr.: nébuleuse ionisée
Fr.: nébuleuse de l'Iris
Same as → NGC 7023.
miq-e surâx-e kelid
Fr.: Nébuleuse du Trou de Serrure
A relatively small and dark cloud of molecules and dust seen silhouetted against the much brighter → Carina Nebula. It contains bright filaments of emitting hot gas and is roughly 7 → light-years in size.
Fr.: nébuleuse de Kleinmann-Law
An strong, extended infrared source in the Orion Nebula, about 1 arcminute NW of the Trapezium and about 12 arcseconds south of the → Becklin-Neugebauer object. It dominates the infrared emission at wavelengths above 20 microns. It probably represents a cluster of young and forming stars embedded in a dusty molecular cloud.
Named after Douglas E. Kleinmann (1942-) and Frank J. Low (1933-), who first studied this object in 1967; → nebula.
Lagoon Nebula (M8, NGC 6523)
miq-e mordâb (#)
Fr.: nébuleuse de la lagune
A giant → H II region lying in the direction of → Sagittarius about 5,000 → light-years away. It represents a giant cloud of interstellar matter which is currently undergoing star formation, and has already formed a considerable cluster of young stars (NGC 6530).
Lyman alpha nebula
Fr.: nébuleuse Lyman alpha
A huge gaseous nebula (≥ 50 kpc) lying at high → redshifts (z ~ 2-6) and strongly emitting radiation due to the → Lyman alpha line (luminosities of ≥ 1043 erg s-1) of hydrogen gas. Also called Lyman alpha blobs, they are thought to lie in massive (M ~ 1013 solar masses) → dark matter halos, which would subsequently evolve into those typical of rich → galactic clusters.
1) A cloud of gas and dust in the interstellar space. There are three
general types: → emission nebulae,
→ reflection nebulae,
and → dark nebulae.
From L. nebula "mist," nimbus "rainstorm, rain cloud;" cognate with Av. napta- "moist," nabās-câ- "cloud," nabah- "sky;" Pers. nam "moisture;" cf. Gk. nephos "cloud, mass of clouds," nephele "cloud;" Skt. nábhas- "moisture, cloud, mist;" O.H.G. nebul; Ger. Nebel "fog;" O.E. nifol "dark;" PIE base *nebh- "cloud, vapor, fog, moist, sky."
Miq "nebula" (used by Tusi, in Pers. translation of Sufi's "Book of Fixed Stars"), variants meh "fog," mož, Tabari miyâ, Lori/Laki (kara) mozy, Ossetic mig/megæ, from Mid.Pers. mēq "cloud, mist;" Av. mēγa- "cloud;" cf. Skt. meghá- "cloud, overcast weather;" Gk. omikhle "mist;" Lith. miglà "mist, haze;" PIE base *mighlā- "cloud."
Of or relating to or resembling a → nebula.
Fr.: continuum nébulaire
Fr.: hypothèse nébulaire
The hypothesis first put forward in the 18-th century that the solar system formed from a primeval nebula around the Sun. Same as the → Kant-Laplace hypothesis.
Fr.: raie nébulaire
A → forbidden line that is found in the spectra of → interstellar → ionized gas. The nebular lines are emitted by several atomic species (e.g. O, O+, O++, N+, S++) and correspond to the → transition from the electronic → metastable state 1D to the → ground state 3P. Examples are the doubly ionized oxygen lines [O III] at 4959 and 5007 Å (→ [O III] doublet) and the ionized nitrogen doublet [N II] at 6548 and 6583 Å. See also → auroral line; → transauroral line.
Fr.: variable nébulaire
A type of eruptive variable star, mainly young FU Orionis and T Tauri types, associated with nebulosity.
North America Nebula
miq-e Âmrikâ-ye hudari
Fr.: Nébuleuse de l'Amérique du Nord
An → H II region in → Cygnus, also known as NGC 7000, resembling the continent North America in long exposure images. This nebula is lying three degrees from bright star → Deneb and spans on the sky over four times the angular size of the full Moon. A dark lane separates the North America Nebula from the → Pelican Nebula, actually part of the same enormous cloud some 2,000 → light-years away.
It was first photographed in 1890 by Max Wolf (1863-1932), a German astronomer, who also first called it the North America Nebula because of its resemblance to the Earth's continent. America, from the feminine of Americus, the Latinized first name of the explorer Amerigo Vespucci (1454-1512), who made two trips to the New World as a navigator and claimed to have discovered it. The name America first appeared on a map in 1507 by the German cartographer Martin Waldseemüller, referring to the area now called Brazil; → nebula.
Fr.: nébuleuse Omega
An → H II region located in the rich star fields of the → Sagittarius area of the Milky Way. Its distance from the Earth is between 5,000 and 6,000 → light-years and spans some 15 light-years in diameter. Its other designations are: Swan Nebula, Messier 17, and NGC 6618.
Omega, Gk. alphabet letter; → nebula.