R136

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R136

Grand star-forming region R136 in NGC 2070 (captured by the Hubble Space Telescope).jpg

The massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. There is no known star-forming region in the Local Group as active and as luminous as 30 Doradus. The image, taken in ultraviolet, visible, and red light by Hubble's Wide Field Camera 3, spans about 100 light-years.
Observation data (J2000.0 epoch)
Constellation Dorado
Right ascension 05h 38m 42.396s
Declination −69° 06′ 03.36″
Distance 157 kly (48.5 kpc)
Apparent magnitude (V) 9.50
Physical characteristics
Other designations [1] UCAC2 1803442, SAO 249329, HD 38268, TYC 9163-1014-1, CD-69 324, GC 7114
See also: Open cluster, List of open clusters

R136 (formally known as RMC 136 from the Radcliffe Observatory Magellanic Clouds catalogue) 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 (20 arc seconds) of the centre of the cluster.[2] The extreme number and concentration of young massive stars in this part of the LMC qualifies it as a starburst region.[3]

Properties[edit]

R136 produces most of the energy that makes the Tarantula Nebula visible. The estimated mass of the cluster is 450,000 solar masses, suggesting it may become a globular cluster in the future.[4] R136 has around 200 times the stellar density of a typical OB association such as Cygnus OB2.[5] The central R136 concentration of the cluster is about 2 parsecs across, although the whole NGC 2070 cluster is much larger.[5]

R136 is thought to be less than 2 million years old, None of the member stars are significantly evolved and none are thought to have exploded as supernovae. The brightest stars are WNh, O supergiants, and OIf/WN slash stars, all extremely massive fully convective stars. There are no red supergiants, blue hypergiants, or luminous blue variables within the cluster. A small number of class B stars have been detected in the outskirts of the cluster, but less massive and less luminous stars cannot be identified at the large distance of the LMC.[2]

Components[edit]

The cluster R136 contains many of the most massive and luminous stars known, including R136a1. Within the central 5 parsecs there are 32 of the hottest type O stars (O2 - O3.5), 40 other O stars, and 12 Wolf-Rayet stars, mostly of the extremely luminous WNh type. Within 150 parsecs there are a further 325 O stars and 19 Wolf-Rayet stars.[2] Several runaway stars have been associated with R136, including VFTS 682.[6]

R136 was first resolved into three components R136a, R136b, and R136c. R136a was resolved using speckle interferometry and eventually space-based observations into eight main components, dominated by R136a1, R136a2, and R136a3, all three being extremely massive WNh stars several million times more luminous than the sun.

NAME Right ascension Declination Apparent magnitude (V) Spectral type Database references
R136a 05h 38m 43.3s −69° 06′ 08″ star cluster SIMBAD
R136a1 (BAT99 108) 05h 38m 42.43s −69° 06′ 02.2″ 12.77 WN5h SIMBAD
R136a2 (BAT99 109) 05h 38m 42.45s −69° 06′ 02.2″ 13.38 WN5h SIMBAD
R136a3 (BAT99 106) 05h 38m 42.291s −69° 06′ 03.45″ 12.93 WN5h SIMBAD
R136 Ab (SNR B0538-69.2) 05h 37m 51.6s −69° 10′ 23″ 9.59 SNR SIMBAD
R136 Ac (PSR J0537-6910) 05h 37m 47.6s −69° 10′ 20″ pulsar SIMBAD
R136b (BAT99 111) 05h 38m 42.78s −69° 06′ 03.1″ 13.66 WN9h SIMBAD
R136c (BAT99 112) 05h 38m 42.896s −69° 06′ 04.92″ 12.86 WN5h SIMBAD


Gallery[edit]

See also[edit]

  • Hodge 301, another star cluster in Tarantula Nebula.

References[edit]

  1. ^ Simbad data for RMC 136
  2. ^ a b c A bot will complete this citation soon. Click here to jump the queuearXiv:1308.3412v1.
  3. ^ doi:10.1086/177507
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  4. ^ 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. arXiv:0811.4748. Bibcode:2009AJ....137.3437B. doi:10.1088/0004-6256/137/2/3437. 
  5. ^ a b doi:10.1086/305126
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  6. ^ doi:10.1088/0004-637X/746/1/15
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  7. ^ "Close Encounter with the Tarantula". ESA/Hubble Picture of the Week. Retrieved 6 August 2012. 

Further reading[edit]

External links[edit]