Emission nebula | |
---|---|
H II region | |
![]() James Webb Space Telescope's NIRCam view of the Tarantula Nebula | |
Observation data: J2000 epoch | |
Right ascension | 05h 38m 38s [1] |
Declination | −69° 05.7′ [1] |
Distance | 160 ± 10 k ly (49 ± 3 [2] [3] k pc) |
Apparent magnitude (V) | +8 [2] |
Apparent dimensions (V) | 40′ × 25′ [2] |
Constellation | Dorado |
Physical characteristics | |
Radius | 931 [2] [4] ly |
Notable features | In LMC |
Designations | NGC 2070, [2] Doradus Nebula, [1] Dor Nebula, [1] 30 Doradus |
The Tarantula Nebula (also known as 30 Doradus) is a large H II region in the Large Magellanic Cloud (LMC), forming its south-east corner (from Earth's perspective).
The Tarantula Nebula was observed by Nicolas-Louis de Lacaille during an expedition to the Cape of Good Hope between 1751 and 1753. He catalogued it as the second of the "Nebulae of the First Class", "Nebulosities not accompanied by any star visible in the telescope of two feet". It was described as a diffuse nebula 20' across. [5]
Johann Bode included the Tarantula in his 1801 Uranographia star atlas and listed it in the accompanying Allgemeine Beschreibung und Nachweisung der Gestirne catalogue as number 30 in the constellation "Xiphias or Dorado". Instead of being given a stellar magnitude, it was noted to be nebulous. [6]
The name Tarantula Nebula arose in the mid 20th century from its appearance in deep photographic exposures. [7]
30 Doradus has often been treated as the designation of a star, [8] [9] or of the central star cluster NGC 2070, [10] but is now generally treated as referring to the whole nebula area of the Tarantula Nebula. [11] [12]
The Tarantula Nebula has an apparent magnitude of 8. Considering its distance of about 49 kpc [2] (160,000 light-years), this is an extremely luminous non-stellar object. Its luminosity is so great that if it were as close to Earth as the Orion Nebula, the Tarantula Nebula would cast visible shadows. [13] In fact, it is the most active starburst region known in the Local Group of galaxies.
It is also one of the largest H II regions in the Local Group with an estimated diameter around 200 to 570 pc (650 to 1860 light years), [2] [3] and also because of its very large size, it is sometimes described as the largest, although other H II regions such as NGC 604, which is in the Triangulum Galaxy, could be larger. [3] The nebula resides on the leading edge of the LMC where ram pressure stripping, and the compression of the interstellar medium likely resulting from this, is at a maximum.
30 Doradus has at its centre the star cluster NGC 2070 which includes the compact concentration of stars known as R136 [14] that produces most of the energy that makes the nebula visible. The estimated mass of the cluster is 450,000 solar masses, suggesting it will likely become a globular cluster in the future. [15] In addition to NGC 2070, the Tarantula Nebula contains a number of other star clusters including the much older Hodge 301. The most massive stars of Hodge 301 have already exploded in supernovae. [16]
The closest supernova observed since the invention of the telescope, [17] Supernova 1987A, occurred in the outskirts of the Tarantula Nebula. [18] There is a prominent supernova remnant enclosing the open cluster NGC 2060, but the remnants of many other supernovae are difficult to detect in the complex nebulosity. [19]
An x-ray quiet black hole was discovered in the Tarantula Nebula, the first outside of the Milky Way Galaxy that does not radiate strongly. The black hole has a mass of at least 9 solar masses and is in a circular orbit with its 25 solar mass blue giant companion VFTS 243. [20]
The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (163,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (c. 16 kiloparsecs (52,000 light-years) away) and the possible dwarf irregular galaxy called the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is about 9.86 kiloparsecs (32,200 light-years) across. It is roughly one-hundredth the mass of the Milky Way and is the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33).
The Triangulum Galaxy is a spiral galaxy 2.73 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC (New General Catalogue) 598. With the D25 isophotal diameter of 18.74 kiloparsecs (61,100 light-years), the Triangulum Galaxy is the third-largest member of the Local Group of galaxies, behind the Andromeda Galaxy and the Milky Way.
An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light years, and density from a few to about a million particles per cubic centimetre. The Orion Nebula, now known to be an H II region, was observed in 1610 by Nicolas-Claude Fabri de Peiresc by telescope, the first such object discovered.
The Sombrero Galaxy is a peculiar galaxy of unclear classification in the constellation borders of Virgo and Corvus, being about 9.55 megaparsecs from the Milky Way galaxy. It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. It has an isophotal diameter of approximately 29.09 to 32.32 kiloparsecs, making it slightly bigger in size than the Milky Way.
Messier 60 or M60, also known as NGC 4649, is an elliptical galaxy approximately 57 million light-years away in the equatorial constellation of Virgo. Together with NGC 4647, it forms a pair known as Arp 116. Messier 60 and nearby elliptical galaxy Messier 59 were discovered by Johann Gottfried Koehler in April 1779, observing a comet in the same part of the sky. Charles Messier added both to his catalogue about three days after this.
The Owl Nebula is a planetary nebula approximately 2,030 light years away in the constellation Ursa Major. Estimated to be about 8,000 years old, it is approximately circular in cross-section with a faint internal structure. It was formed from the outflow of material from the stellar wind of the central star as it evolved along the asymptotic giant branch. The nebula is arranged in three concentric shells, with the outermost shell being about 20–30% larger than the inner shell. The owl-like appearance of the nebula is the result of an inner shell that is not circularly symmetric, but instead forms a barrel-like structure aligned at an angle of 45° to the line of sight.
Messier 108 is a barred spiral galaxy about 28 million light-years away from Earth in the northern constellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the Earth, this galaxy is seen almost edge-on.
NGC 3603 is a nebula situated in the Carina–Sagittarius Arm of the Milky Way around 20,000 light-years away from the Solar System. It is a massive H II region containing a very compact open cluster HD 97950.
Sher 25 is a blue supergiant star in the constellation Carina, located approximately 25,000 light years from the Sun in the H II region NGC 3603 of the Milky Way. It is a spectral type B1Iab star with an apparent magnitude of 12.2. Its initial main sequence mass is calculated at 60 times the mass of the Sun, but a star of this type will have already lost a substantial fraction of that mass. It is unclear whether Sher 25 has been through a red supergiant phase or has just evolved from the main sequence, so the current mass is very uncertain.
R136 is the central concentration of stars in the NGC 2070 star cluster, which lies at the centre of the Tarantula Nebula in the Large Magellanic Cloud. When originally named it was an unresolved stellar object but is now known to include 72 class O and Wolf–Rayet stars within 5 parsecs of the centre of the cluster. The extreme number and concentration of young massive stars in this part of the LMC qualifies it as a starburst region.
NGC 2060 is a star cluster within the Tarantula Nebula in the Large Magellanic Cloud, very close to the larger NGC 2070 cluster containing R136. It was discovered by John Herschel in 1836. It is a loose cluster approximately 10 million years old, within one of the Tarantula Nebula's superbubbles formed by the combined stellar winds of the cluster or by old supernovae.
R136b is a blue supergiant star in the R136 cluster in the Large Magellanic Cloud. It is one of the most massive and most luminous stars known. It is found in the dense R136 open cluster at the centre of NGC 2070 in the Tarantula Nebula.
R136a1 is one of the most massive and luminous stars known, at nearly 200 M☉ and nearly 4.7 million L☉, and is also one of the hottest, at around 46,000 K. It is a Wolf–Rayet star at the center of R136, the central concentration of stars of the large NGC 2070 open cluster in the Tarantula Nebula in the Large Magellanic Cloud. The cluster can be seen in the far southern celestial hemisphere with binoculars or a small telescope, at magnitude 7.25. R136a1 itself is 100 times fainter than the cluster and can only be resolved using speckle interferometry.
VFTS 682 is a Wolf–Rayet star in the Large Magellanic Cloud. It is located over 29 parsecs (95 ly) north-east of the massive cluster R136 in the Tarantula Nebula. It is 138 times the mass of the sun and 3.2 million times more luminous which makes it one of the most massive and most luminous stars known.
R136a2 is a Wolf-Rayet star residing near the center of the R136, the central concentration of stars of the large NGC 2070 open cluster in the Tarantula Nebula, a massive H II region in the Large Magellanic Cloud which is a nearby satellite galaxy of the Milky Way. It has one of the highest confirmed masses and luminosities of any known star, at about 151 M☉ and 3.5 million L☉ respectively.
R136a3 is a Wolf–Rayet star in R136, a massive star cluster located in Dorado. It is located near R136a1, the most massive and luminous star known. R136a3 is itself one of the most massive and most luminous stars known at about 179 times more massive and 5 million times more luminous than the Sun.
BAT99-98 is a Wolf–Rayet star located in the Large Magellanic Cloud, in NGC 2070 near the R136 cluster in the Tarantula Nebula. At 226 M☉ and 5,000,000 L☉ it is one of the most massive and luminous stars currently known.
30 Doradus .. 49 kpc +- 3 kpc
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