# Astronomy:Tarantula Nebula

Short description: H II region in the constellation Dorado
Tarantula Nebula
Emission nebula
H II region
The Tarantula Nebula, first light image of the TRAPPIST national telescope at La Silla Observatory
Credit: TRAPPIST/E. Jehin/ESO
Observation data: J2000 epoch
Right ascension 05h 38m 38s[1]
Declination−69° 05.7′[1]
Distance160 ± 10 k ly   (49 ± 3[2][3] k pc)
Apparent magnitude (V)+8[2]
Apparent dimensions (V)40′ × 25′[2]
Physical characteristics
Notable featuresIn LMC
DesignationsNGC 2070,[2] Doradus Nebula,[1] Dor Nebula,[1] 30 Doradus

The Tarantula Nebula (also known as 30 Doradus) is an H II region in the Large Magellanic Cloud (LMC), from the Solar System's perspective forming its south-east corner.

## Discovery

File:Hubble WFC3 30 Doradus Zoom.ogv 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 the mid 20th century from the 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]

## Properties

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,[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.

## NGC 2070

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]

## Supernova 1987A

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]

## References

1. "Results for Tarantula Nebula". "30 Doradus .. 49 kpc +- 3 kpc"
2. Lebouteiller, V.; Bernard-Salas, J.; Brandl, B.; Whelan, D. G. et al. (June 2008). "Chemical Composition and Mixing in Giant H II Regions: NGC 3603, 30 Doradus, and N66". The Astrophysical Journal 680 (1): 398–419. doi:10.1086/587503. Bibcode2008ApJ...680..398L.
3. distance × sin( diameter_angle / 2 ) = 931 ly. radius
4. Jones, K. G. (1969). "The search for the nebulae - VI". Journal of the British Astronomical Association 79: 213. Bibcode1969JBAA...79..213J.
5. Feast, M. W. (1961). "A Study of the 30 Doradus Region of the Large Magellanic Cloud". Monthly Notices of the Royal Astronomical Society 122: 1–16. doi:10.1093/mnras/122.1.1. Bibcode1961MNRAS.122....1F.
6. Pickering, E. C.; Fleming, W. P. (1897). "Large Magellanic Cloud". Astrophysical Journal 6: 459. doi:10.1086/140426. Bibcode1897ApJ.....6..459P.
7. Burnham, S. W. (1893). "New Double Stars, discovered in 1892, and measures". Monthly Notices of the Royal Astronomical Society 53: 273. doi:10.1093/mnras/53.4.273. Bibcode1893MNRAS..53..273B.
8. Andersen, M.; Zinnecker, H.; Moneti, A.; McCaughrean, M. J.; Brandl, B.; Brandner, W.; Meylan, G.; Hunter, D. (2009). "The Low-Mass Initial Mass Function in the 30 Doradus Starburst Cluster". The Astrophysical Journal 707 (2): 1347–1360. doi:10.1088/0004-637X/707/2/1347. Bibcode2009ApJ...707.1347A.
9. Walborn, N. R. (1984). "The stellar content of 30 Doradus". Structure and Evolution of the Magellanic Clouds. 108. 243–253. doi:10.1007/978-94-010-9801-4_59. ISBN 978-90-277-1723-8. Bibcode1984IAUS..108..243W.
10. Aguirre, J. E.; Bezaire, J. J.; Cheng, E. S.; Cottingham, D. A.; Cordone, S. S.; Crawford, T. M.; Fixsen, D. J.; Knox, L. et al. (2003). "The Spectrum of Integrated Millimeter Flux of the Magellanic Clouds and 30 Doradus from Top Hat and DIRBE Data". The Astrophysical Journal 596 (1): 273–286. doi:10.1086/377601. Bibcode2003ApJ...596..273A.
11. Massey, P; Hunter, D. (January 1998). "Star Formation in R136: A Cluster of O3 Stars Revealed by Hubble Space Telescope Spectroscopy". The Astrophysical Journal 493 (1): 180. doi:10.1086/305126. Bibcode1998ApJ...493..180M.
12. Bosch, Guillermo; Terlevich, Elena; Terlevich, Roberto (2009). "Gemini/GMOS Search for Massive Binaries in the Ionizing Cluster of 30 Dor". Astronomical Journal 137 (2): 3437–3441. doi:10.1088/0004-6256/137/2/3437. Bibcode2009AJ....137.3437B.
13. Grebel, Eva K.; Chu, You-Hua (2000). "Hubble Space Telescope Photometry of Hodge 301: An "Old" Star Cluster in 30 Doradus". Astronomical Journal 119 (2): 787–799. doi:10.1086/301218. Bibcode2000AJ....119..787G.
14. Couper, Heather; Henbest, Nigel (2009). Encyclopedia of Space. DK Publishing. p. 299. ISBN 978-0-7566-5600-3.
15. Lazendic, J. S.; Dickel, J. R.; Jones, P. A. (2003). "Supernova Remnant Candidates in the 30 Doradus Nebula". The Astrophysical Journal 596 (1): 287. doi:10.1086/377630. Bibcode2003ApJ...596..287L.