وسترلوند 1
وسترلوند 1 Westerlund 1 (تسمى أيضاً عنقود آرا Ara Cluster،[4] designated Wd1) is a compact young super star cluster في مجرة درب التبانة، على بعد نحو 3.5–5 kpc من الأرض. It is one of the most massive young star clusters in the Milky Way,[3] and was discovered by Bengt Westerlund in 1961[5] but remained largely unstudied for many years due to high interstellar absorption in its direction. In the future, it will probably evolve into a globular cluster.[6]
| Westerlund 1 | |
|---|---|
 الفضل: ESO/VPHAS+ Survey/N. Wright | |
| بيانات الرصد (J2000 الحقبة) | |
| الكوكبة | آرا |
| الصعود المستقيم | 16h 47m 04.0s[1] |
| الميل | −45° 51′ 04.9″[1] |
| المسافة | 12.1±2.0[2] (3.7±0.6 kpc) |
| السمات الطبيعية | |
| الكتلة | 63,000[3] M☉ |
| نصف القطر | 3.26[3] |
| العمر المقدر | 3.50 Myr[3] |
| تسميات أخرى | عنقود آرا، وسترلوند 1، ESO 277-12, C 1644-457, VDBH 197 |
The cluster contains a large number of rare, evolved, high-mass stars, including: 6 yellow hypergiants, 4 red supergiants including Westerlund 1-26, one of the largest known stars, 24 Wolf-Rayet stars, a luminous blue variable, many OB supergiants, and an unusual supergiant sgB[e] star which has been proposed to be the remnant of a recent stellar merger.[7] In addition, X-ray observations have revealed the presence of the anomalous X-ray pulsar CXO J164710.2-455216, a slow rotating neutron star that must have formed from a high-mass progenitor star.[8] Westerlund 1 is believed to have formed in a single burst of star formation, implying the constituent stars have similar ages and compositions.
Aside from hosting some of the most massive and least-understood stars in our galaxy, Westerlund 1 is useful as a relatively nearby, easy to observe super star cluster that can help astronomers determine what occurs within extragalactic super star clusters.
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الرصد
الهامش
- ^ أ ب خطأ استشهاد: وسم
<ref>غير صحيح؛ لا نص تم توفيره للمراجع المسماةbrandner - ^ Koumpia, E.; Bonanos, A. Z. (2012). "Fundamental parameters of four massive eclipsing binaries in Westerlund 1". Astronomy & Astrophysics. 547: A30. arXiv:1108.4453. Bibcode:2012A&A...547A..30K. doi:10.1051/0004-6361/201219465.
- ^ أ ب ت ث Portegies Zwart, Simon F.; McMillan, Stephen L.W.; Gieles, Mark (2010). "Young Massive Star Clusters". Annual Review of Astronomy and Astrophysics. 48: 431. arXiv:1002.1961. Bibcode:2010ARA&A..48..431P. doi:10.1146/annurev-astro-081309-130834.
- ^ Westerlund, B. E. (1968). "On the Extended Infrared Source in ARA". Astrophysical Journal. 154: L67. Bibcode:1968ApJ...154L..67W. doi:10.1086/180270.
- ^ Westerlund, B. (1961). "A Heavily Reddened Cluster in Ara". Astronomical Journal. 70: 57. Bibcode:1961AJ.....66T..57W. doi:10.1086/108585.
- ^ Gallagher; Grebel (2002). "Extragalactic Star Clusters: Speculations on the Future". Extragalactic Star Clusters, IAU Symposium. 207: 207. arXiv:astro-ph/0109052. Bibcode:2002IAUS..207..745G.
{{cite journal}}: Unknown parameter|last-author-amp=ignored (|name-list-style=suggested) (help) - ^ Clark, J. S.; Negueruela, I.; Crowther, P. A.; Goodwin, S. P.; et al. (2005). "On the massive stellar population of the super star cluster Westerlund 1". Astronomy & Astrophysics. 434 (3): 949–969. arXiv:astro-ph/0504342. Bibcode:2005A&A...434..949C. doi:10.1051/0004-6361:20042413.
- ^ Muno, Michael P.; Clark, J. Simon; Crowther, Paul A.; Dougherty, Sean M.; De Grijs, Richard; Law, Casey; McMillan, Stephen L. W.; Morris, Mark R.; Negueruela, Ignacio; Pooley, David; Portegies Zwart, Simon; Yusef-Zadeh, Farhad; et al. (2006). "A Neutron Star with a Massive Progenitor in Westerlund 1". Astrophysical Journal Letters. 636 (1): L41. arXiv:astro-ph/0509408. Bibcode:2006ApJ...636L..41M. doi:10.1086/499776.