Westerhout 49-2

From Wikipedia, the free encyclopedia
Westerhout 49-2
Observation data
Epoch J2000      Equinox J2000
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[a] R☉
Luminosity4,365,000 L☉
Temperature35,500 K
Other designations
TIC 202340617, 2MASS J19102185+0905025
Database references
SIMBADdata

Westerhout 49-2 (W49-2) is a 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.[2]

Properties[]

Westerhout 49-2 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. Westerhout 49-2 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][a]

Uncertainties[]

There is significant uncertainty about Westerhout 49-2'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. ^ a b Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:

References[]

  1. ^ a b Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  2. ^ a b c d e f 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. arXiv:1602.05190. Bibcode:2016A&A...589A..16W. doi:10.1051/0004-6361/201527823. ISSN 0004-6361. S2CID 59425112.
Retrieved from ""