2MASS J0523-1403

**2MASS J0523−1403**
观测资料; 历元 J2000
星座	天兔座
星官
赤经	05h 23m 38.2236232872s
赤纬	−14° 03′ 02.017758240″
视星等（V）	21.05
特性
光谱分类	L2.5V
天体测定
径向速度 (Rv)	12.21 ± 0.09 km/s
自行 (μ)	赤经：107.254±0.290 mas/yr ; 赤纬：160.897±0.341 mas/yr
视差 (π)	78.3632 ± 0.1855 mas
距离	41.62 ± 0.10 ly ; (12.76 ± 0.03 pc)
绝对星等 (MV)	20.6
详细资料
表面重力 (log g)	5.21±0.16
亮度	0.000138 L☉
温度	1939±68 K
自转速度 (v sin i)	21 km/s
其他命名
	2MASS J05233822−1403022、2MUCD 10390、B2006 J052338.2−140302、2MASSI J0523382−140302、USNO-B1.0 0759−00062850
参考资料库
SIMBAD	资料

2MASS J0523−1403是一颗位于南天星座天兔座，距离地球大约40光年，质量非常小的红矮星^[7]。它的视星等非常黯淡，只有21.05等，表面有效温度仅2,074K，要对红外线敏感的大型望远镜才看得见它。这颗恒星是在2微米全天巡天（2MASS）时首度观测到^[8]。

特征

2MASS J0523−1403的亮度约为0.000126 L_☉，半径为0.086 R_☉，和有效温度2,074 K。这些数值都是目前所知主序星的最低值^[2]。它的光谱类型为L2.5，V-K色指数为9.42 ^[2]。质量推算为7001675400000000000♠67.54±12.79 M_J（6998644000000000000♠0.0644±0.0122 M_☉）^[5]。哈伯太空望远镜观测在0.15角秒的范围之外没有伴星存在^[9]。在2004年经由甚大天线阵（VLA，Very Large Array）检测到零星的电波辐射^[10]。 H-α的辐射也被检测到，而这是色球活动的一个迹象^[6]。

氢融合极限

近星研究会（RECONS）的成员最近确认2MASS J0523-1403可能是最小恒星的代表^[11]。它的半径－亮度和半径－温度都是本地最小的^[2]。由于主序星和棕矮星的半径－质量关系不同，本地最小值发生在氢燃烧的极限。与棕矮星不同的是，它们的核心由简并压力支撑，所以棕矮星的半径随著质量增加而减小。即当棕矮星的质量增加，也增加了简并的分数，导致半径随著质量的增加而缩小^[11]。理论估计恒星的最低质量在0.07至0.077M_☉之间，与2MASS J0523-1403的质量与此相符^[2]。

参考资料

^ ^1.0 ^1.1 2MASS J05233822-1403022. SIMBAD. Centre de données astronomiques de Strasbourg. [14 December 2013]. （原始内容存档于2016-04-16）.
^ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 Dieterich, Sergio B.; Henry, Todd J.; Jao, Wei-Chun; Winters, Jennifer G.; Hosey, Altonio D.; Riedel, Adric R.; Subasavage, John P. The Solar Neighborhood XXXII. The Hydrogen Burning Limit. The Astronomical Journal. May 2014, 147 (5). article id 94. Bibcode:2014AJ....147...94D. arXiv:1312.1736 . doi:10.1088/0004-6256/147/5/94.
^ Blake, Cullen H.; Charbonneau, David; White, Russel J. The NIRSPEC Ultracool Dwarf Radial Velocity Survey. The Astrophysical Journal. 2010, 723 (1): 684–706. Bibcode:2010ApJ...723..684B. arXiv:1008.3874 . doi:10.1088/0004-637X/723/1/684.
^ ^4.0 ^4.1 ^4.2 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天体在盖亚望远镜第二批数据发布的记录
^ ^5.0 ^5.1 ^5.2 ^5.3 Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime. The Astrophysical Journal. 2015, 810 (2): 158. doi:10.1088/0004-637X/810/2/158.
^ ^6.0 ^6.1 Reiners, A.; Basri, G. Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs. The Astrophysical Journal. 2008, 684 (2): 1390–1403. Bibcode:2008ApJ...684.1390R. arXiv:0805.1059v2 . doi:10.1086/590073.
^ Star - How do we know that 2MASS J0523-1403 is a red dwarf?. [2022-04-26]. （原始内容存档于2021-05-14）.
^ Cruz, Kelle L.; Reid, I. Neill; Liebert, James; Kirkpatrick, J. Davy; Lowrance, Patrick J. Meeting the Cool Neighbors. V. A 2MASS-Selected Sample of Ultracool Dwarfs. The Astronomical Journal. 2003, 126 (5): 2421–2448. Bibcode:2003AJ....126.2421C. arXiv:astro-ph/0307429 . doi:10.1086/378607.
^ Reid, I. Neill; Lewitus, E.; Allen, P. R.; Cruz, Kelle L.; Burgasser, Adam J. A Search for Binary Systems among the Nearest L Dwarfs. The Astronomical Journal. 2006, 132 (2): 891–901. Bibcode:2006AJ....132..891R. arXiv:astro-ph/0606331 . doi:10.1086/505626.
^ Antonova, A.; Doyle, J. G.; Hallinan, G.; Golden, A.; Koen, C. Sporadic long-term variability in radio activity from a brown dwarf. Astronomy and Astrophysics. 2 September 2007, 472 (1): 257–260. Bibcode:2007A&A...472..257A. arXiv:0707.0634 . doi:10.1051/0004-6361:20077231.
^ ^11.0 ^11.1 Garmany, Katy. NOAO/SOAR: Where do stars end and brown dwarfs begin? (新闻稿). National Optical Astronomy Observatory. 9 December 2013 [14 December 2013]. （原始内容存档于2020-01-12）.

外部链接

[SIMBAD-1] 1.0 ^1.1 2MASS J05233822-1403022. SIMBAD. Centre de données astronomiques de Strasbourg. [14 December 2013]. （原始内容存档于2016-04-16）.

[Dieterich_2013-2] 2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 Dieterich, Sergio B.; Henry, Todd J.; Jao, Wei-Chun; Winters, Jennifer G.; Hosey, Altonio D.; Riedel, Adric R.; Subasavage, John P. The Solar Neighborhood XXXII. The Hydrogen Burning Limit. The Astronomical Journal. May 2014, 147 (5). article id 94. Bibcode:2014AJ....147...94D. arXiv:1312.1736 . doi:10.1088/0004-6256/147/5/94.

[Blake_2010-3] Blake, Cullen H.; Charbonneau, David; White, Russel J. The NIRSPEC Ultracool Dwarf Radial Velocity Survey. The Astrophysical Journal. 2010, 723 (1): 684–706. Bibcode:2010ApJ...723..684B. arXiv:1008.3874 . doi:10.1088/0004-637X/723/1/684.

[dr2-4] 4.0 ^4.1 ^4.2 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天体在盖亚望远镜第二批数据发布的记录

[filippazzo-5] 5.0 ^5.1 ^5.2 ^5.3 Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime. The Astrophysical Journal. 2015, 810 (2): 158. doi:10.1088/0004-637X/810/2/158.

[Reiners_2008-6] 6.0 ^6.1 Reiners, A.; Basri, G. Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs. The Astrophysical Journal. 2008, 684 (2): 1390–1403. Bibcode:2008ApJ...684.1390R. arXiv:0805.1059v2 . doi:10.1086/590073.

[7] Star - How do we know that 2MASS J0523-1403 is a red dwarf?. [2022-04-26]. （原始内容存档于2021-05-14）.

[Cruz_2003-8] Cruz, Kelle L.; Reid, I. Neill; Liebert, James; Kirkpatrick, J. Davy; Lowrance, Patrick J. Meeting the Cool Neighbors. V. A 2MASS-Selected Sample of Ultracool Dwarfs. The Astronomical Journal. 2003, 126 (5): 2421–2448. Bibcode:2003AJ....126.2421C. arXiv:astro-ph/0307429 . doi:10.1086/378607.

[Reid_2006-9] Reid, I. Neill; Lewitus, E.; Allen, P. R.; Cruz, Kelle L.; Burgasser, Adam J. A Search for Binary Systems among the Nearest L Dwarfs. The Astronomical Journal. 2006, 132 (2): 891–901. Bibcode:2006AJ....132..891R. arXiv:astro-ph/0606331 . doi:10.1086/505626.

[Antonova_2007-10] Antonova, A.; Doyle, J. G.; Hallinan, G.; Golden, A.; Koen, C. Sporadic long-term variability in radio activity from a brown dwarf. Astronomy and Astrophysics. 2 September 2007, 472 (1): 257–260. Bibcode:2007A&A...472..257A. arXiv:0707.0634 . doi:10.1051/0004-6361:20077231.

[Garmany_2013-11] 11.0 ^11.1 Garmany, Katy. NOAO/SOAR: Where do stars end and brown dwarfs begin? (新闻稿). National Optical Astronomy Observatory. 9 December 2013 [14 December 2013]. （原始内容存档于2020-01-12）.

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观测资料历元 J2000
星座	天兔座
星官
赤经	05^h 23^m 38.2236232872^s^[1]
赤纬	−14° 03′ 02.017758240″^[1]
视星等（V）	21.05^[2]
特性
光谱分类	L2.5V^[2]
天体测定

径向速度 (R_v)	12.21 ± 0.09^[3] km/s
自行 (μ)	赤经：7002107254000000000♠107.254±0.290^[4] mas/yr 赤纬：7002160897000000000♠160.897±0.341^[4] mas/yr
视差 (π)	78.3632 ± 0.1855^[4] mas
距离	41.62 ± 0.10 ly (12.76 ± 0.03 pc)
绝对星等 (M_V)	20.6^[2]

详细资料

表面重力 (log g)	7000521000000000000♠5.21±0.16^[5]
亮度	0.000138^[5] L_☉
温度	7003193900000000000♠1939±68^[5] K
自转速度 (v sin i)	21^[6] km/s

其他命名
2MASS J05233822−1403022、2MUCD 10390、B2006 J052338.2−140302、2MASSI J0523382−140302、USNO-B1.0 0759−00062850
参考资料库
SIMBAD	资料

特征

氢融合极限

相关条目

参考资料

外部链接