NGC 346是位于杜鹃座的一个年轻 疏散星团,是与小麦哲伦星系(SMC)的星云相关的恒星集团[4]。它是由苏格兰天文学家詹姆士·敦洛普于1826年8月1日发现的。约翰·路易·埃米尔·德雷耳描述其为“明亮、大、非常不规则的图形,中间明亮得多,类似于双星,有斑点但未能分辨”[5]。星团周边是小麦哲伦星系中最亮的恒星之一:多星系统HD 5980[6]

NGC 346
哈伯太空望远镜拍摄的NGC 346
Credit: HST/NASA/ESA
观测资料 (J2000 历元)
星座杜鹃座[1]
赤经00h 59m 05.090s[2]
赤纬−72° 10′ 33.24″[2]
距离210,000 光年
物理特征
值得注意特征电离氢区
其他特征ESO 51-10,[3] N66
相关条目:疏散星团NGC天体表

该星团位于小麦哲伦星系中最亮,命名为N66的电离氢区中心附近[7]。它位于这个星系棒的东北部分[8],恒星调查已经在这个星团的方向上发现了230颗大质量的OB星[4]。33个星团成员是O型星,其中有11颗是O6.5型或更早[8]。星团的内部15 pc半径看起来集中凝聚,而该体积外部的区域则较为分散[9]。中心附近最年轻的星团成员年龄不到200万岁[7],观测结果表明,该星团仍在进行高效率的恒星形成[7]。星团的形成速率估计为(4±1)×10−3 太阳质量/年[9]

图集 编辑

显著的恒星[10]
Walborn ELS MPG NMC SSN 光谱
类型
有效
温度 (K)
绝对
星等
热星等 质量
(M)
207758 755
(HD 5980/AB5)
LBV
WN4
OI
45,000
45,000
34,000
−7.1
(−8.1) −6.8
−6.7
−11.135
−10.885
−9.885
61
66
34
1 435 26 7 O5.5If 43,400 −6.7 −10.7 91
1 789 5 O7If 38,900 −7 −10.7 85
3 355 29 9 O3V 51,300 −5.7 −10.3 76
6 7 324 32 13 O4V 48,600 −5.2 −9.6 54
4 342 30 11 O5.5V 44,900 −5.5 −9.7 53
368 28 15 O5.5V 44,900 −5 −9.2 43
2 470 25 O8.5III 35,700 −5.4 −8.9 34

参考资料 编辑

  1. ^ Hubble Heritage Site. Results for NGC 346. [2007-04-03]. (原始内容存档于2009-02-11). 
  2. ^ 2.0 2.1 Sturm, R.; et al. The XMM-Newton survey of the Small Magellanic Cloud: The X-ray point-source catalogue. Astronomy & Astrophysics. October 2013, 558: 31. Bibcode:2013A&A...558A...3S. S2CID 118620464. arXiv:1307.7594 . doi:10.1051/0004-6361/201219935. A3. 
  3. ^ NGC 346. SIMBAD. 斯特拉斯堡天文资料中心. 
  4. ^ 4.0 4.1 Dufton, P. L.; et al. The NGC 346 massive star census. Nitrogen abundances for apparently single, narrow lined, hydrogen core burning B-type stars. Astronomy & Astrophysics. February 2020, 634: 15. Bibcode:2020A&A...634A...6D. S2CID 209376523. arXiv:1912.07539 . doi:10.1051/0004-6361/201936921. A6. 
  5. ^ Seligman, Courtney. New General Catalogue objects: NGC 300 - 349. cseligman.com. [2020-09-17]. (原始内容存档于2023-07-29). 
  6. ^ Nazé, Y.; et al. An X-Ray Investigation of the NGC 346 Field in the Small Magellanic Cloud I. The Luminous Blue Variable HD 5980 and the NGC 346 Cluster. The Astrophysical Journal. November 2002, 580 (1): 225–234. Bibcode:2002ApJ...580..225N. S2CID 118907796. arXiv:astro-ph/0208289 . doi:10.1086/343079. 
  7. ^ 7.0 7.1 7.2 Dufton, P. L.; et al. A census of massive stars in NGC 346. Stellar parameters and rotational velocities. Astronomy & Astrophysics. June 2019, 626: 28. Bibcode:2019A&A...626A..50D. S2CID 148571638. arXiv:1905.03359 . doi:10.1051/0004-6361/201935415. A50. 
  8. ^ 8.0 8.1 Rubio, M.; et al. Massive young stellar objects in the N 66/NGC 346 region of the SMC. Astronomy & Astrophysics. July 2018, 615: 9. Bibcode:2018A&A...615A.121R. S2CID 119190580. arXiv:1803.10833 . doi:10.1051/0004-6361/201730487. A121. 
  9. ^ 9.0 9.1 Hony, S.; et al. Star formation rates from young-star counts and the structure of the ISM across the NGC 346/N66 complex in the SMC. Monthly Notices of the Royal Astronomical Society. April 2015, 448 (2): 1847–1862. Bibcode:2015MNRAS.448.1847H. arXiv:1501.03634 . doi:10.1093/mnras/stv107. 
  10. ^ Massey, Philip; Waterhouse, Elizabeth; DeGioia-Eastwood, Kathleen. The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turnoffs. I. Results from 19 OB Associations in the Magellanic Clouds. The Astronomical Journal. May 2000, 119 (5): 2214–2241. Bibcode:2000AJ....119.2214M. ISSN 0004-6256. S2CID 16891188. arXiv:astro-ph/0002233 . doi:10.1086/301345. 

外部链接 编辑