2MASS J09393548−2448279

**2MASS J09393548−2448279**
觀測資料; 曆元 J2000
星座	唧筒座
星官
赤經	09h 39m 35.48s
赤緯	−24° 48′ 27.9″
視星等（V）
特性
光谱分类	T8
视星等 (J)	15.61 ± 0.09
视星等 (H)	15.96 ± 0.09
视星等 (K)	16.83 ± 0.09
天体测定
自行 (μ)	赤经：+573.4 ± 2.3 mas/yr ; 赤纬：−1044.7 ± 2.5 mas/yr
视差 (π)	187.3 ± 4.6 mas
距离	17.4 ± 0.4 ly ; (5.3 ± 0.1 pc)
詳細資料
2MASS 0939-2448 A
表面重力 (log g)	4.88+0.2; −0.4
亮度	0.000002 L☉
溫度	611+17; −24 K
金屬量	−0.3–0.0
年齡	2–10 Gyr
2MASS 0939-2448 B
半徑	0.09 R☉
溫度	600–700 K
金屬量	−0.3–0.0
年齡	2–10 Gyr
其他命名
	2MASS J09393548−2448279
參考資料庫
SIMBAD	资料
	2MASS 0939−2448 2MASS 0939−2448在唧筒座的位置;

2MASS J09393548−2448279 (縮寫為 2MASS 0939−2448)^[4] 位於唧筒座的兩顆T型褐矮星雙星系統, 距離地球只有16.6光年^[2]，兩顆恆星的軌道距離為0.0928AU。

發現

2005年，2MASS 0939−2448 通過2微米全天巡天被確定為褐矮星。^[4]

特性

模型計算表明，2MASS 0939−2448 是一個由兩顆褐矮星組成的系統，有效溫度約為500和700K，質量約為木星質量的25和40；它也可能是一對相同的物體，溫度為600K，質量為30個木星。^[1]

已知最暗的褐矮星

從2005年發現到至少 2008 年，2MASS 0939−2448 或其較暗的部分是已知最暗的褐矮星。^[5] 後來透過廣域紅外線巡天探測衛星發現了較暗的天體，包括（亞）褐矮星和新光譜類Y的流氓行星。在 2011-2014 年，這些天體中已知最暗的是WISE 1828+2650，從 2014 年開始最暗的是WISE 0855−0714。

參考資料

^ ^1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 ^1.10 Leggett, Sandy K.; Cushing, Michael C.; Saumon, Didier; Marley, Mark S.; Roellig, Thomas L.; Warren, Stephen J.; Burningham, Ben; Jones, Hugh R. A.; Kirkpatrick, J. Davy; Lodieu, Nicolas; Lucas, Philip W.; Mainzer, Amy K.; Martín, Eduardo L.; McCaughrean, Mark J.; Pinfield, David J.; Sloan, Gregory C.; Smart, Richard L.; Tamura, Motohide; Van Cleve, Jeffrey E. The Physical Properties of Four ~600 K T Dwarfs. The Astrophysical Journal. 2009, 695 (2): 1517–1526. Bibcode:2009ApJ...695.1517L. S2CID 44050900. arXiv:0901.4093 . doi:10.1088/0004-637X/695/2/1517.
^ ^2.0 ^2.1 ^2.2 ^2.3 Burgasser, Adam J.; Tinney, C. G.; Cushing, Michael C.; Saumon, Didier; Marley, Mark S.; Bennett, Clara S.; Kirkpatrick, J. Davy. 2MASS J09393548-2448279: The Coldest and Least Luminous Brown Dwarf Binary Known? (PDF). The Astrophysical Journal. 2008, 689 (1): L53–L56 [2023-03-20]. Bibcode:2008ApJ...689L..53B. doi:10.1086/595747 . （原始内容存档 (PDF)于2022-01-28）.
^ 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, S2CID 89611607, arXiv:1508.01767 , doi:10.1088/0004-637X/810/2/158
^ ^4.0 ^4.1 ^4.2 Tinney, C. G.; Burgasser, Adam J.; Kirkpatrick, J. Davy; McElwain, Michael W. The 2MASS Wide-Field T Dwarf Search. IV. Hunting Out T Dwarfs with Methane Imaging. The Astronomical Journal. 2005, 130 (5): 2326–2346. Bibcode:2005AJ....130.2326T. S2CID 119451860. arXiv:astro-ph/0508150 . doi:10.1086/491734.
^ Astronomers Find the Two Dimmest Stellar Bulbs (新闻稿). NASA/JPL. 2008-12-10 [2008-12-20]. （原始内容存档于2021-10-06）.

Faherty, Jacqueline K.; Burgasser, Adam J.; Walter, Frederick M.; Van der Bliek, Nicole; Shara, Michael M.; Cruz, Kelle L.; West, Andrew A.; Vrba, Frederick J.; Anglada-Escud, Guillem. The Brown Dwarf Kinematics Project (BDKP). III. Parallaxes for 70 Ultracool Dwarfs. The Astrophysical Journal. 2012, 752 (1): 56. Bibcode:2012ApJ...752...56F. S2CID 18160586. arXiv:1203.5543 . doi:10.1088/0004-637X/752/1/56.
Smart, R. L.; Tinney, C. G.; Bucciarelli, B.; Marocco, F.; Abbas, U.; Andrei, A.; Bernardi, G.; Burningham, B.; Cardoso, C.; Costa, E.; Crosta, M. T.; Daprá, M.; Day-Jones, A.; Goldman, B.; Jones, H. R. A.; Lattanzi, M. G.; Leggett, S. K.; Lucas, P.; Mendez, R.; Penna, J. L.; Pinfield, D.; Smith, L.; Sozzetti, A.; Vecchiato, A. NPARSEC: NTT Parallaxes of Southern Extremely Cool objects. Goals, targets, procedures and first results. Monthly Notices of the Royal Astronomical Society. 2013, 433 (3): 2054–2063. Bibcode:2013MNRAS.433.2054S. S2CID 1376087. arXiv:1306.4527 . doi:10.1093/mnras/stt876.

[Leggett2009-1] 1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 ^1.10 Leggett, Sandy K.; Cushing, Michael C.; Saumon, Didier; Marley, Mark S.; Roellig, Thomas L.; Warren, Stephen J.; Burningham, Ben; Jones, Hugh R. A.; Kirkpatrick, J. Davy; Lodieu, Nicolas; Lucas, Philip W.; Mainzer, Amy K.; Martín, Eduardo L.; McCaughrean, Mark J.; Pinfield, David J.; Sloan, Gregory C.; Smart, Richard L.; Tamura, Motohide; Van Cleve, Jeffrey E. The Physical Properties of Four ~600 K T Dwarfs. The Astrophysical Journal. 2009, 695 (2): 1517–1526. Bibcode:2009ApJ...695.1517L. S2CID 44050900. arXiv:0901.4093 . doi:10.1088/0004-637X/695/2/1517.

[Burgasser2008-2] 2.0 ^2.1 ^2.2 ^2.3 Burgasser, Adam J.; Tinney, C. G.; Cushing, Michael C.; Saumon, Didier; Marley, Mark S.; Bennett, Clara S.; Kirkpatrick, J. Davy. 2MASS J09393548-2448279: The Coldest and Least Luminous Brown Dwarf Binary Known? (PDF). The Astrophysical Journal. 2008, 689 (1): L53–L56 [2023-03-20]. Bibcode:2008ApJ...689L..53B. doi:10.1086/595747 . （原始内容存档 (PDF)于2022-01-28）.

[Filippazzo2015-3] 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, S2CID 89611607, arXiv:1508.01767 , doi:10.1088/0004-637X/810/2/158

[Tinney2005-4] 4.0 ^4.1 ^4.2 Tinney, C. G.; Burgasser, Adam J.; Kirkpatrick, J. Davy; McElwain, Michael W. The 2MASS Wide-Field T Dwarf Search. IV. Hunting Out T Dwarfs with Methane Imaging. The Astronomical Journal. 2005, 130 (5): 2326–2346. Bibcode:2005AJ....130.2326T. S2CID 119451860. arXiv:astro-ph/0508150 . doi:10.1086/491734.

[5] Astronomers Find the Two Dimmest Stellar Bulbs (新闻稿). NASA/JPL. 2008-12-10 [2008-12-20]. （原始内容存档于2021-10-06）.

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2MASS J09393548−2448279

發現

特性

已知最暗的褐矮星

參考資料

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