Astronomy:R136

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Short description: Super star cluster in the constellation Dorado, in the Large Magellanic Cloud


R136
Grand star-forming region R136 in NGC 2070 (captured by the Hubble Space Telescope).jpg
In ultraviolet, visible, and red light by Hubble Space Telescope Wide Field Camera 3
Credit: NASA, ESA
Observation data (J2000.0 epoch)
ConstellationDorado
Right ascension 05h 38m 42.396s[1]
Declination−69° 06′ 03.36″[1]
Distance157 kly (48.5 kpc)
Apparent magnitude (V)9.50
Physical characteristics
Mass90,000[2] M
Estimated age1.5+0.3
−0.7
million years[2]
Other designationsUCAC2 1803442, SAO 249329, HD 38268, TYC 9163-1014-1, CD-69 324, GC 7114[3]
See also: Open cluster, List of open clusters

R136 (formerly known as RMC 136 from the Radcliffe Observatory Magellanic Clouds catalogue[4]) 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 (catalogued as HD 38268 and Wolf-Rayet star Brey 82) 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.[5] The extreme number and concentration of young massive stars in this part of the LMC qualifies it as a starburst region.[6]

Properties

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.[7] R136 has around 200 times the stellar density of a typical OB association such as Cygnus OB2.[8] The central R136 concentration of the cluster is about 2 parsecs across, although the whole NGC 2070 cluster is much larger.[8]

R136 is thought to be less than 2 million years old.[8][9] None of the member stars is significantly evolved and none is thought to have exploded as supernova. 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 resolved from the dense cluster core at the large distance of the LMC.[5]

R136a

R136a is the bright knot at the centre of R136. It consists of eight extremely massive stars, three of them Wolf-Rayet stars and the rest early O-class stars.[2]

Components

The cluster 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 (O2.0–3.5), 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.[5] Several runaway stars have been associated with R136, including VFTS 682.[10] R136 was first resolved into three components R136a, R136b, and R136c. R136a was resolved using speckle interferometry and eventually space-based observations into as many as 24 components,[11] dominated by R136a1, R136a2, and R136a3, all three being extremely massive WNh stars several million times more luminous than the sun.[12]

Basic data for the original RMC 136 a, b, and c stars
Name Right ascension[5] Declination[5] V[2] (F555W) Spectral type[12] MV[13] (F555W) Temperature (K)[12][14] Luminosity (L)[12][14] Mass (M)[12][14]
R136a1  05h 38m 42.39s −69° 06′ 02.91″ 12.28 WN5h −8.18 46,000 4,677,000 196
R136a2  05h 38m 42.40s −69° 06′ 02.88″ 12.80 WN5h −7.80 50,000 3,548,000 151
R136a3  05h 38m 42.33s −69° 06′ 03.27″ 12.97 WN5h −7.52 50,000 3,631,000 155
R136a4  05h 38m 42.34s −69° 06′ 02.60″ 13.96 O3 V((f*))(n) −6.68 50,000 1,905,000 108
R136a5  05h 38m 42.43s −69° 06′ 02.73″ 13.71 O2I(n)f* −6.86 48,000 2,089,000 116
R136a6  05h 38m 42.29s −69° 06′ 03.37″ 13.35 O2I(n)f*p −6.46 52,000 1,738,000 105
R136a7  05h 38m 42.41s −69° 06′ 02.57″ 13.97 O3III(f*) −6.59 54,000 2,291,000 127
R136a8  05h 38m 42.37s −69° 06′ 01.9″? 14.42 O2–3V[2] −6.05[2] 49,500 1,479,000 96
R136b  05h 38m 42.74s −69° 06′ 03.78″ 13.24 O4If −7.70 35,500 2,239,000 92
R136c  05h 38m 42.90s −69° 06′ 04.83″ 12.86 WN5h[15] −7.9[5] 42,170[15] 3,802,000[15] 142[15]

Gallery

See also

References

  1. 1.0 1.1 Høg, E.; Fabricius, C.; Makarov, V.V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (January 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars – Letter to the Editor". Astronomy and Astrophysics 355: L27-L30. Bibcode2000A&A...355L..27H. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Crowther, Paul A.; Caballero-Nieves, S. M.; Bostroem, K. A.; Maíz Apellániz, J.; Schneider, F. R. N.; Walborn, N. R.; Angus, C. R.; Brott, I. et al. (2016). "The R136 star cluster dissected with Hubble Space Telescope/STIS. I. Far-ultraviolet spectroscopic census and the origin of He II λ1640 in young star clusters". Monthly Notices of the Royal Astronomical Society 458 (1): 624–659. doi:10.1093/mnras/stw273. Bibcode2016MNRAS.458..624C. 
  3. "RMC 136". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=RMC+136. 
  4. Feast, M. W.; Thackeray, A. D.; Wesselink, A. J. (1960). "The brightest stars in the Magellanic Clouds". Monthly Notices of the Royal Astronomical Society 121 (4): 337. doi:10.1093/mnras/121.4.337. Bibcode1960MNRAS.121..337F. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 Doran, E. I.; Crowther, P. A.; de Koter, A.; Evans, C. J.; McEvoy, C.; Walborn, N. R.; Bastian, N.; Bestenlehner, J. M. et al. (2013). "The VLT-FLAMES Tarantula Survey - XI. A census of the hot luminous stars and their feedback in 30 Doradus". Astronomy & Astrophysics 558: A134. doi:10.1051/0004-6361/201321824. Bibcode2013A&A...558A.134D. 
  6. Brandl, B.; Sams, B. J.; Bertoldi, F.; Eckart, A.; Genzel, R.; Drapatz, S.; Hofmann, R.; Loewe, M. et al. (1996). "Adaptive Optics Near-Infrared Imaging of R136 in 30 Doradus: The Stellar Population of a Nearby Starburst". The Astrophysical Journal 466: 254. doi:10.1086/177507. Bibcode1996ApJ...466..254B. 
  7. 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. 
  8. 8.0 8.1 8.2 Massey, P.; Hunter, D. A. (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. 
  9. Crowther, P. A.; Schnurr, O.; Hirschi, R.; Yusof, N.; Parker, R. J.; Goodwin, S. P.; Kassim, H. A. (2010). "The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 M stellar mass limit". Monthly Notices of the Royal Astronomical Society 408 (2): 731. doi:10.1111/j.1365-2966.2010.17167.x. Bibcode2010MNRAS.408..731C. 
  10. Banerjee, S.; Kroupa, P.; Oh, S. (2012). "Runaway Massive Stars from R136: Vfts 682 is Very Likely A "Slow Runaway"". The Astrophysical Journal 746 (1): 15. doi:10.1088/0004-637X/746/1/15. Bibcode2012ApJ...746...15B. 
  11. Campbell, B.; Hunter, D. A.; Holtzman, J. A.; Lauer, T. R.; Shayer, E. J.; Code, A.; Faber, S. M.; Groth, E. J. et al. (November 1992). "Hubble Space Telescope Planetary Camera images of R136". The Astronomical Journal 104 (5): 1721-1742. doi:10.1086/116355. Bibcode1992AJ....104.1721C. https://authors.library.caltech.edu/52364/1/1992AJ____104_1721C.pdf. 
  12. 12.0 12.1 12.2 12.3 12.4 Brands, S.; de Koter, A.; Bestenlehner, J.; Crowther, P. O; Sundqvist, J.; Puls, J.; Caballero-Nieves, S.; Abdul-Masih, M. et al. (7 April 2022). "The R136 star cluster dissected with Hubble Space Telescope/STIS. III. The most massive stars and their clumped winds". Astronomy & Astrophysics 663: A36. doi:10.1051/0004-6361/202142742. ISSN 0004-6361. Bibcode2022A&A...663A..36B. https://www.aanda.org/10.1051/0004-6361/202142742. 
  13. Bestenlehner, Joachim M.; Crowther, Paul A.; Caballero-Nieves, Saida M.; Schneider, Fabian R. N.; Simón-Díaz, Sergio; Brands, Sarah A.; De Koter, Alex; Gräfener, Götz et al. (2020). "The R136 star cluster dissected with Hubble Space Telescope/STIS. II. Physical properties of the most massive stars in R136". Monthly Notices of the Royal Astronomical Society 499 (2): 1918. doi:10.1093/mnras/staa2801. Bibcode2020MNRAS.499.1918B. 
  14. 14.0 14.1 14.2 Kalari, Venu M.; Horch, Elliott P.; Salinas, Ricardo; Vink, Jorick S.; Andersen, Morten; Bestenlehner, Joachim M.; Rubio, Monica (26 July 2022). "Resolving the Core of R136 in the Optical". The Astrophysical Journal 935 (2): 162. doi:10.3847/1538-4357/ac8424. Bibcode2022ApJ...935..162K. 
  15. 15.0 15.1 15.2 15.3 Schneider, F. R. N.; Sana, H.; Evans, C. J.; Bestenlehner, J. M.; Castro, N.; Fossati, L.; Gräfener, G.; Langer, N. et al. (2018). "An excess of massive stars in the local 30 Doradus starburst". Science 359 (6371): 69–71. doi:10.1126/science.aan0106. PMID 29302009. Bibcode2018Sci...359...69S. 
  16. NASA; ESA; Crowther, P. (17 March 2016). "R136 observed with WFC3". https://esahubble.org/images/heic1605a/. 

Further reading

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