Westerlund 1-237 (commonly abbreviated to Wd 1-237) or Westerlund 1 BKS B is a possible red supergiant (RSG) in the constellation of Ara. It is one out of four known red supergiants in the Westerlund 1super star cluster, although its outlying position, spectrum, and parallax, suggest it could be a foreground giant.[10] As a red supergiant, it would be one of the largest known stars and one of the most luminous of its type.[7]
Westerlund 1-237
Westerlund 1 super star cluster. The location of Wd 1-237 is circled. Credit: ESO
Westerlund 1-237 compared to the other 3 RSGs (Red Supergiants) in the Westerlund 1 star cluster.
Westerlund 1-237 is classified as a luminous cool supergiant emitting most of its energy in the infrared spectrum.[11] It is surrounded by a radio nebula which is similar in mass to those of Westerlund 1-20 and Westerlund 1 W26, and moreover directly comparable to that of VY Canis Majoris. The elliptical structure of this nebula however indicates that it has been less affected by the cluster wind of Westerlund 1 (W20 and W26 have pronounced cometary shaped nebulae). The outflow velocity for the RSG wind is assumed to be around 30 km/s. The nebula itself seems to have a mass of 0.07 M☉ and a radius of about 0.11 parsecs. This results in a kinematic age around 3,600 years and a time averaged mass loss rate of 2×10−5M☉ per year.[12]
The star occupies the upper right corner of the Hertzsprung-Russell diagram. With an effective temperature of 3,550 K and a bolometric luminosity of 219,000 L☉, the radius of Westerlund 1-237 would be 1,241 times the solar radius (R☉), making it larger than the orbit of Jupiter. The initial mass of W237 has been calculated from its position relative to theoretical stellar evolutionary tracks to be around 28 M☉ or 32 M☉ for a non-rotating star.[9]
Distance
The distance of Westerlund 1-237 is assumed to be around 8,500+2,000 −1,300light years or 2,600+600 −400parsecs[13] based on it being commonly thought of as a member of the Westerlund 1 star cluster (the elliptical shape of its nebula indicates that it might not be near the center of W1, while other RSGs like W20 and W26 are).[12] Another but older source suggests a similar distance of 3,000±500 parsecs.[7]
Westerlund's 1987 analysis assigned a spectral type of M6+ III to W1-237 and considered it to be a foreground giant with a luminosity only around 1,000 L☉.[2]Gaia Data Release 2 gives a parallax of 1.64±0.2608 mas for W1-237, implying a distance of 623+139 −96pc and a luminosity of 7,178–7,379 L☉ with a corresponding radius of 216 R☉.[14][8] In 2020, the parallax was revised to the much smaller value of 0.3370±0.1235 mas.[6]
^ abBonanos, Alceste Z. (2007). "Variability of Young Massive Stars in the Galactic Super Star Cluster Westerlund 1". The Astronomical Journal. 133 (6): 2696–2708. arXiv:astro-ph/0702614. Bibcode:2007AJ....133.2696B. doi:10.1086/518093. S2CID 119074868.
^ abcWesterlund, B. E. (1987). "Photometry and spectroscopy of stars in the region of a highly reddened cluster in ARA". Astronomy and Astrophysics. Supplement. 70 (3): 311–324. Bibcode:1987A&AS...70..311W. ISSN 0365-0138.
^Clark, J. S.; Ritchie, B. W.; Negueruela, I. (2010). "A serendipitous survey for variability amongst the massive stellar population of Westerlund 1". Astronomy and Astrophysics. 514: A87. arXiv:1003.5107. Bibcode:2010A&A...514A..87C. doi:10.1051/0004-6361/200913820. S2CID 14780809.
^Bonanos, Alceste Z. (2007). "Variability of Young Massive Stars in the Galactic Super Star Cluster Westerlund 1". The Astronomical Journal. 133 (6): 2696–2708. arXiv:astro-ph/0702614. Bibcode:2007AJ....133.2696B. doi:10.1086/518093. S2CID 119074868.
^ abcCutri, 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.
^ abcdeBrown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
^ abcFok, Thomas K. T.; Nakashima, Jun-Ichi; Yung, Bosco H. K.; Hsia, Chih-Hao; Deguchi, Shuji (2012). "Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Associated with Massive Clusters". The Astrophysical Journal. 760 (1): 65. arXiv:1209.6427. Bibcode:2012ApJ...760...65F. doi:10.1088/0004-637X/760/1/65. S2CID 53393926.
^ abcdefMessineo, M.; Brown, A. G. A. (2019). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal. 158 (1): 20. arXiv:1905.03744. Bibcode:2019AJ....158...20M. doi:10.3847/1538-3881/ab1cbd. S2CID 148571616.
^ abcdefArévalo, Aura (2019). The Red Supergiants in the Supermassive Stellar Cluster Westerlund 1 (Thesis). doi:10.11606/D.14.2019.tde-12092018-161841.
^"APOD: 2017 June 20 - The Massive Stars in Westerlund 1". apod.nasa.gov. Retrieved 2020-06-21.
^ abDougherty, S. M.; Clark, J. S.; Negueruela, I.; Johnson, T.; Chapman, J. M. (2010-02-01). "Radio emission from the massive stars in the galactic super star cluster Westerlund 1". Astronomy & Astrophysics. 511: A58. arXiv:0912.4165. Bibcode:2010A&A...511A..58D. doi:10.1051/0004-6361/200913505. ISSN 0004-6361. S2CID 9792700.
^Aghakhanloo, Mojgan; Murphy, Jeremiah W.; Smith, Nathan; Parejko, John; Díaz-Rodríguez, Mariangelly; Drout, Maria R.; Groh, Jose H.; Guzman, Joseph; Stassun, Keivan G. (2020-02-21). "Inferring the parallax of Westerlund 1 from Gaia DR2". Monthly Notices of the Royal Astronomical Society. 492 (2): 2497–2509. arXiv:1901.06582. Bibcode:2020MNRAS.492.2497A. doi:10.1093/mnras/stz3628. ISSN 0035-8711. S2CID 119465620.
^Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Mantelet, G.; Andrae, R. (2018). "Estimating Distance from Parallaxes. IV. Distances to 1.33 Billion Stars in Gaia Data Release 2". The Astronomical Journal. 156 (2): 58. arXiv:1804.10121. Bibcode:2018AJ....156...58B. doi:10.3847/1538-3881/aacb21. S2CID 119289017.
May 06, 2023
westerlund, commonly, abbreviated, westerlund, possible, supergiant, constellation, four, known, supergiants, westerlund, super, star, cluster, although, outlying, position, spectrum, parallax, suggest, could, foreground, giant, supergiant, would, largest, kno. Westerlund 1 237 commonly abbreviated to Wd 1 237 or Westerlund 1 BKS B is a possible red supergiant RSG in the constellation of Ara It is one out of four known red supergiants in the Westerlund 1 super star cluster although its outlying position spectrum and parallax suggest it could be a foreground giant 10 As a red supergiant it would be one of the largest known stars and one of the most luminous of its type 7 Westerlund 1 237Westerlund 1 super star cluster The location of Wd 1 237 is circled Credit ESOObservation dataEpoch J2000 Equinox J2000Constellation AraRight ascension 16h 47m 03 1075sDeclination 45 52 18 9572 Apparent magnitude V 19 008 1 CharacteristicsEvolutionary stage either a red supergiant or a foreground giant 2 Spectral type M3Ia 3 or M6 III 4 Apparent magnitude B 22 8 citation needed Apparent magnitude J 5 075 5 Apparent magnitude H 3 01 5 Apparent magnitude K 2 18 5 Apparent magnitude G 11 259 6 Apparent magnitude R 13 634 1 AstrometryProper motion m RA 3 09 0 15 6 mas yr Dec 4 12 0 12 6 mas yrParallax p 0 3370 0 1235 mas 6 Distance3 000 7 or 623 8 pcAbsolute magnitude MV 6 96 9 Detailsif a supergiantRadius1 241 70 9 R Luminosity219 000 26 000 9 L Temperature3 550 9 3 605 8 KAge7 9 9 Myrif a foreground giantRadius216 8 R Luminosity1 000 2 or 7 178 7 379 8 L Temperature3 605 8 KOther designationsWesterlund 1 W237 Westerlund 1 BKS B 2MASS J16470309 4552189 Gaia EDR3 5940105904023386752Database referencesSIMBADdata Contents 1 Physical characteristics 2 Distance 3 See also 4 ReferencesPhysical characteristics Edit Westerlund 1 237 compared to the other 3 RSGs Red Supergiants in the Westerlund 1 star cluster Westerlund 1 237 is classified as a luminous cool supergiant emitting most of its energy in the infrared spectrum 11 It is surrounded by a radio nebula which is similar in mass to those of Westerlund 1 20 and Westerlund 1 W26 and moreover directly comparable to that of VY Canis Majoris The elliptical structure of this nebula however indicates that it has been less affected by the cluster wind of Westerlund 1 W20 and W26 have pronounced cometary shaped nebulae The outflow velocity for the RSG wind is assumed to be around 30 km s The nebula itself seems to have a mass of 0 07 M and a radius of about 0 11 parsecs This results in a kinematic age around 3 600 years and a time averaged mass loss rate of 2 10 5 M per year 12 The star occupies the upper right corner of the Hertzsprung Russell diagram With an effective temperature of 3 550 K and a bolometric luminosity of 219 000 L the radius of Westerlund 1 237 would be 1 241 times the solar radius R making it larger than the orbit of Jupiter The initial mass of W237 has been calculated from its position relative to theoretical stellar evolutionary tracks to be around 28 M or 32 M for a non rotating star 9 Distance EditThe distance of Westerlund 1 237 is assumed to be around 8 500 2 000 1 300 light years or 2 600 600 400 parsecs 13 based on it being commonly thought of as a member of the Westerlund 1 star cluster the elliptical shape of its nebula indicates that it might not be near the center of W1 while other RSGs like W20 and W26 are 12 Another but older source suggests a similar distance of 3 000 500 parsecs 7 Westerlund s 1987 analysis assigned a spectral type of M6 III to W1 237 and considered it to be a foreground giant with a luminosity only around 1 000 L 2 Gaia Data Release 2 gives a parallax of 1 64 0 2608 mas for W1 237 implying a distance of 623 139 96 pc and a luminosity of 7 178 7 379 L with a corresponding radius of 216 R 14 8 In 2020 the parallax was revised to the much smaller value of 0 3370 0 1235 mas 6 See also EditWesterlund 1 75References Edit a b Bonanos Alceste Z 2007 Variability of Young Massive Stars in the Galactic Super Star Cluster Westerlund 1 The Astronomical Journal 133 6 2696 2708 arXiv astro ph 0702614 Bibcode 2007AJ 133 2696B doi 10 1086 518093 S2CID 119074868 a b c Westerlund B E 1987 Photometry and spectroscopy of stars in the region of a highly reddened cluster in ARA Astronomy and Astrophysics Supplement 70 3 311 324 Bibcode 1987A amp AS 70 311W ISSN 0365 0138 Clark J S Ritchie B W Negueruela I 2010 A serendipitous survey for variability amongst the massive stellar population of Westerlund 1 Astronomy and Astrophysics 514 A87 arXiv 1003 5107 Bibcode 2010A amp A 514A 87C doi 10 1051 0004 6361 200913820 S2CID 14780809 Bonanos Alceste Z 2007 Variability of Young Massive Stars in the Galactic Super Star Cluster Westerlund 1 The Astronomical Journal 133 6 2696 2708 arXiv astro ph 0702614 Bibcode 2007AJ 133 2696B doi 10 1086 518093 S2CID 119074868 a b c 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 a b c d e Brown A G A et al Gaia collaboration 2021 Gaia Early Data Release 3 Summary of the contents and survey properties Astronomy amp Astrophysics 649 A1 arXiv 2012 01533 Bibcode 2021A amp A 649A 1G doi 10 1051 0004 6361 202039657 S2CID 227254300 Erratum doi 10 1051 0004 6361 202039657e Gaia EDR3 record for this source at VizieR a b c Fok Thomas K T Nakashima Jun Ichi Yung Bosco H K Hsia Chih Hao Deguchi Shuji 2012 Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Associated with Massive Clusters The Astrophysical Journal 760 1 65 arXiv 1209 6427 Bibcode 2012ApJ 760 65F doi 10 1088 0004 637X 760 1 65 S2CID 53393926 a b c d e f Messineo M Brown A G A 2019 A Catalog of Known Galactic K M Stars of Class I Candidate Red Supergiants in Gaia DR2 The Astronomical Journal 158 1 20 arXiv 1905 03744 Bibcode 2019AJ 158 20M doi 10 3847 1538 3881 ab1cbd S2CID 148571616 a b c d e f Arevalo Aura 2019 The Red Supergiants in the Supermassive Stellar Cluster Westerlund 1 Thesis doi 10 11606 D 14 2019 tde 12092018 161841 APOD 2017 June 20 The Massive Stars in Westerlund 1 apod nasa gov Retrieved 2020 06 21 Cl Westerlund 1 W 237 Simbad a b Dougherty S M Clark J S Negueruela I Johnson T Chapman J M 2010 02 01 Radio emission from the massive stars in the galactic super star cluster Westerlund 1 Astronomy amp Astrophysics 511 A58 arXiv 0912 4165 Bibcode 2010A amp A 511A 58D doi 10 1051 0004 6361 200913505 ISSN 0004 6361 S2CID 9792700 Aghakhanloo Mojgan Murphy Jeremiah W Smith Nathan Parejko John Diaz Rodriguez Mariangelly Drout Maria R Groh Jose H Guzman Joseph Stassun Keivan G 2020 02 21 Inferring the parallax of Westerlund 1 from Gaia DR2 Monthly Notices of the Royal Astronomical Society 492 2 2497 2509 arXiv 1901 06582 Bibcode 2020MNRAS 492 2497A doi 10 1093 mnras stz3628 ISSN 0035 8711 S2CID 119465620 Bailer Jones C A L Rybizki J Fouesneau M Mantelet G Andrae R 2018 Estimating Distance from Parallaxes IV Distances to 1 33 Billion Stars in Gaia Data Release 2 The Astronomical Journal 156 2 58 arXiv 1804 10121 Bibcode 2018AJ 156 58B doi 10 3847 1538 3881 aacb21 S2CID 119289017 Retrieved from https en wikipedia org w index php title Westerlund 1 237 amp oldid 1152238337, wikipedia, wiki, book, books, library,
