2MASP J0345432+254023

**2MASP J0345432+254023**
观测资料; 历元 J2000
星座	金牛座
星官
赤经	03h 45m 43.2s
赤纬	25° 40′ 23″
视星等（V）
参考数据库
SIMBAD	资料

2MASP J0345432+254023（2MASP J0345, 2M0345+25）是一颗光谱类型为L0的棕矮星，位于金牛座昴宿星团的区域内，距离地球大约88光年^[1]。它不是昴宿星团的成员，只是一颗在星团前方的前景星^[2]（昴宿星团的距离远了好几倍－大约400光年，并且有不同的自行－向东南方，而2M0345+25是朝向西方移动^[1]。）

观测的历史

发现

2M0345+25是在1997年被Kirkpatrick 等人发现的，它是第一颗被发现的独立晚M型棕矮星。最初估计它的光谱类型为≥M10 V^[2]。

距离

目前对2M0345+25最精确的距离估计是使用三角视差，在美国海军天文台的暗星视差测量专案下完成的，并由Dahn等人在2003年发表：37.1 ± 0.5 mas，相当于87.9 ± 1.2光年。

2M0345+25 距离估计

来源	视差，mas	距离，秒差距	距离，光年	参考资料
Kirkpatrick et al. (1997)		≲21	≲68.5	^[2]
Kirkpatrick et al. (1999)	35.5 ± 0.8	28.2 ± 0.6	91.9+2.1 −2.0	^[3]
Dahn et al. (2002)	37.1 ± 0.5	27.0 ± 0.4	87.9 ± 1.2	^[1]

非三角视差的距离估计使用斜体字标示。最好的估计值使用"黑体"。

参考资料

^ ^1.0 ^1.1 ^1.2 Dahn, Conard C.; Harris, Hugh C.; Vrba, Frederick J.; Guetter, Harry H.; Canzian, Blaise; Henden, Arne A.; Levine, Stephen E.; Luginbuhl, Christian B.; Monet, Alice K. B. Astrometry and Photometry for Cool Dwarfs and Brown Dwarfs. The Astronomical Journal. 2002, 124 (2): 1170. ISSN 1538-3881. doi:10.1086/341646.
^ ^2.0 ^2.1 ^2.2 Kirkpatrick, J. Davy; Beichman, Charles A.; Skrutskie, Michael F. The Coolest Isolated M Dwarf and Other 2MASS Discoveries. The Astrophysical Journal. 1997, 476 (1): 311. ISSN 0004-637X. doi:10.1086/303613.
^ Kirkpatrick, J. Davy; Reid, I. Neill; Liebert, James; Cutri, Roc M.; Nelson, Brant; Beichman, Charles A.; Dahn, Conard C.; Monet, David G.; Gizis, John E. Dwarfs Cooler than "M": The Definition of Spectral Type "L" Using Discoveries from the 2-Micron All-Sky Survey (2MASS). The Astrophysical Journal. 1999, 519 (2): 802. ISSN 0004-637X. doi:10.1086/307414.

[Dahn2002-1] 1.0 ^1.1 ^1.2 Dahn, Conard C.; Harris, Hugh C.; Vrba, Frederick J.; Guetter, Harry H.; Canzian, Blaise; Henden, Arne A.; Levine, Stephen E.; Luginbuhl, Christian B.; Monet, Alice K. B. Astrometry and Photometry for Cool Dwarfs and Brown Dwarfs. The Astronomical Journal. 2002, 124 (2): 1170. ISSN 1538-3881. doi:10.1086/341646.

[Kirkpatrick1997-2] 2.0 ^2.1 ^2.2 Kirkpatrick, J. Davy; Beichman, Charles A.; Skrutskie, Michael F. The Coolest Isolated M Dwarf and Other 2MASS Discoveries. The Astrophysical Journal. 1997, 476 (1): 311. ISSN 0004-637X. doi:10.1086/303613.

[Kirkpatrick1999-3] Kirkpatrick, J. Davy; Reid, I. Neill; Liebert, James; Cutri, Roc M.; Nelson, Brant; Beichman, Charles A.; Dahn, Conard C.; Monet, David G.; Gizis, John E. Dwarfs Cooler than "M": The Definition of Spectral Type "L" Using Discoveries from the 2-Micron All-Sky Survey (2MASS). The Astrophysical Journal. 1999, 519 (2): 802. ISSN 0004-637X. doi:10.1086/307414.

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