Astronomy:WBB2016 2

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Short description: Blue supergiant in the constellation Aquila
WBB2016 2
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquila
Right ascension  19h 10m 21.858s[1]
Declination 09° 05′ 02.53″[1]
Characteristics
Spectral type O2-3.5If*[2]
Astrometry
Distance36,200 ly
(11,100[2] pc)
Details[2]
Mass250±120 (90–240) M☉
Radius55.41[lower-alpha 1] R☉
Luminosity4,365,000 L☉
Temperature35,500 K
Other designations
[WBB2016] 2, 2MASS J19102185+0905025
Database references
SIMBADdata

[WBB2016] 2 is an very massive and luminous star in the H II region Westerhout 49. At a mass of 250 solar masses (although with significant uncertainty) and a luminosity of over 4 million L☉, it is one of the most massive and most luminous stars known (possibly the most massive), and possibly the most massive one located within our galaxy.[2]

Properties

[WBB2016] 2 is located within the H II region Westerhout 49, about 11.1 kiloparsecs from the Sun. The star is heavily reddened, and it is reddened in the K band by nearly 5 magnitudes, the most of any star in the region. [WBB2016] 2 is classified as an evolved slash star, with a spectral type of O2-3.5If*. The star is one of the most luminous stars known, with a luminosity of 4,365,000 L☉, and has a temperature of about 35,500 K, corresponding to a radius of over 55 times that of the Sun.[2]

Uncertainties

There is significant uncertainty about [WBB2016] 2's properties. For example, its luminosity may be anywhere between 2,455,000 L☉ and 7,763,000 L☉. Moreover, there is even greater uncertainty about its mass, which may be anywhere between 110 and 370 M☉, though it's more likely to be between 90 and 240 M☉.[2]

Notes

  1. ↑ Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:
    (5772/35,500)4*4,365,000=55.41 R⊙

References

  1. ↑ 1.0 1.1 Cutri, R. M.; Skrutskie, M. F.; van Dyk, S.; Beichman, C. A.; Carpenter, J. M.; Chester, T.; Cambresy, L.; Evans, T. et al. (2003-06-01). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". VizieR Online Data Catalog: II/246. Bibcode: 2003yCat.2246....0C. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Wu, Shi-Wei; Bik, Arjan; Bestenlehner, Joachim M.; Henning, Thomas; Pasquali, Anna; Brandner, Wolfgang; Stolte, Andrea (2016-05-01). "The massive stellar population of W49: A spectroscopic survey". Astronomy and Astrophysics 589: A16. doi:10.1051/0004-6361/201527823. ISSN 0004-6361. Bibcode: 2016A&A...589A..16W.