GJ 440

**LP 145-141**
觀測資料; 曆元 J2000.0 (ICRS)
星座	苍蝇座
星官
赤經	11h 45m 42.9205s
赤緯	−64° 50′ 29.459″
視星等（V）	11.50
特性
光谱分类	DQ6
U−B 色指数	-0.59
B−V 色指数	+0.19
天体测定
自行 (μ)	赤经：2665.25 mas/yr ; 赤纬：-346.19 mas/yr
视差 (π)	215.6753 ± 0.0181 mas
距离	15.123 ± 0.001 ly ; (4.6366 ± 0.0004 pc)
詳細資料
質量	0.56 ± 0.08 M☉
半徑	0.01 R☉
表面重力 (log g)	8.27 ± 0.05
亮度	0.0005 L☉
溫度	8,500 ± 300 K
年齡	(白矮星年齡); 1.44 Gyr
其他命名
	GJ 440、HIP 57367、BPM 7108、Ci 20 658、EGGR 82、L 145-141、LAWD 37、LHS 43、LP 145-141、LPM 396、LTT 4364、NLTT 28447、PLX 2716、PM 11429-6434、WD 1142-645、TYC 8981-4417-1、GSC 08981-04418、2MASS J11454297-6450297
參考資料庫
SIMBAD	资料
	LP 145-141 GJ 440在苍蝇座的位置;

天球赤道座標： 11^h 45^m 42.9205^s，−64° 50′ 29.459″

LP 145-141 (亦可稱為GJ 440、LAWD 37^[15])是一顆位於苍蝇座的白矮星，距離太陽系15光年。^[16] 根據 2009 年的一篇論文，它是已知白矮星之中距離太陽第四近的 (由近至遠依次為天狼星B，南河三B和范馬南星。)^[17]

空間運動

GJ 440可能是Wolf219移動星群的成員，該群有七個可能的成員。這些恆星在太空中有相似的運動，這可能表明它們有共同的起源。^[18] 這些恆星的估計空間速度為160公里/秒，並且沿著一條高度偏心的軌道穿過銀河系。^[19]

特性

白矮星不再通過核聚變在其核心產生能量，而是穩定地散發掉它們剩餘的熱量。GJ 440有一個 DQ光譜分類，表明它是一種罕見的白矮星，在其光譜中顯示出原子或分子碳的證據。^[20]

2019 年，觀察到GJ 440從一顆更遠的恆星前經過。哈勃太空望遠鏡觀測到的GJ 440的引力場使星光發生彎曲，從而可以直接測量其質量。GJ 440的估計質量為 0.56±0.08M☉，符合具有碳氧核心的白矮星的預期範圍。這一測量標誌著首次直接測定單個白矮星的引力質量。^[5]

它是一顆估計有 4.4 個太陽質量的大質量主序星的恆星殘骸。^[21] 雖然它在主序帶上，但它可能是一顆光譜B 級恆星（在 B4-B9 範圍內）。^[22] 恆星的大部分原始質量在進入漸近巨星分支階段後，就在成為白矮星之前脫落。

伴星搜索

哈勃太空望遠鏡的一項調查顯示，在探測範圍內沒有可見的軌道伴星。^[23]^[3]

它的距離、質量和溫度使它被認為是尋找類木行星的一個很好的候選者。它相對較大的質量和較高的溫度意味著該系統的壽命相對較短，因此起源較晚。^[24]

參見

鄰近恆星列表

參考資料

^ Constellation boundaries. Centre de Données astronomiques de Strasbourg. [2007-07-16]. （原始内容存档于2019-07-17）.
^ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 LAWD 37. SIMBAD. 斯特拉斯堡天文資料中心. [2007-07-16].
^ ^3.0 ^3.1 Daniel J. Schroeder; et al. A Search for Faint Companions to Nearby Stars Using the Wide Field Planetary Camera 2. The Astronomical Journal. February 2000, 119 (2): 906–922. Bibcode:2000AJ....119..906S. doi:10.1086/301227 .
^ Brown, A. G. A.; et al. Gaia Early Data Release 3: Summary of the contents and survey properties. Astronomy & Astrophysics. 2021, 649: A1. Bibcode:2021A&A...649A...1G. S2CID 227254300. arXiv:2012.01533 . doi:10.1051/0004-6361/202039657 . 已忽略未知参数|collaboration= (帮助) (勘误: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
^ ^5.0 ^5.1 McGill, P.; Anderson, J.; Casertano, S.; Sahu, K.C., First semi-empirical test of the white dwarf mass-radius relationship using a single white dwarf via astrometric microlensing, Monthly Notices of the Royal Astronomical Society, March 2023, 520 (1): 259–280 [2023-02-08], doi:10.1093/mnras/stac3532
^ ^6.0 ^6.1 ^6.2 ^6.3 Table 2, P. Bergeron; S. K. Leggett; María Teresa Ruiz. Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements. Astrophysical Journal Supplement Series. April 2001, 133 (2): 413–449. Bibcode:2001ApJS..133..413B. S2CID 15511301. arXiv:astro-ph/0011286 . doi:10.1086/320356.
^ Gliese, W.; Jahreiß, H. Gl 440. Preliminary Version of the Third Catalogue of Nearby Stars. 1991 [2023-03-20]. （原始内容存档于2016-03-04）.
^ Perryman; et al. HIP 57367. The Hipparcos and Tycho Catalogues. 1997 [2023-03-20]. （原始内容存档于2016-03-04）.
^ Porter, J. G.; Yowell, E. J.; Smith, E. S. A catalogue of 1474 stars with proper motion exceeding four-tenths year.. Publications of the Cincinnati Observatory. 1930, 20: 1–32. Bibcode:1930PCinO..20....1P. Page 16 (Ci 20 658). （页面存档备份，存于互联网档案馆）
^ Luyten, Willem Jacob. LHS 30. LHS Catalogue, 2nd Edition. 1979 [2023-03-20]. （原始内容存档于2016-03-04）.
^ Luyten, Willem Jacob. NLTT 28447. NLTT Catalogue. 1979 [2023-03-20]. （原始内容存档于2016-03-04）.
^ Van Altena W. F.; Lee J. T.; Hoffleit E. D. GCTP 2716. The General Catalogue of Trigonometric Stellar Parallaxes Fourth. 1995 [2023-03-20]. （原始内容存档于2016-03-04）.
^ Perryman; et al. HIP 57367. The Hipparcos and Tycho Catalogues. 1997 [2023-03-20]. （原始内容存档于2016-03-04）.
^ Hog; et al. TYC 8981-4417-1. The Tycho-2 Catalogue. 2000 [2023-03-20]. （原始内容存档于2016-03-04）.
^ Lawd 37. [2023-03-20]. （原始内容存档于2023-03-21）.
^ Henry, Todd J.; Walkowicz, Lucianne M.; Barto, Todd C.; Golimowski, David A. The Solar Neighborhood. VI. New Southern Nearby Stars Identified by Optical Spectroscopy. The Astronomical Journal. April 2002, 123 (4): 2002–2009. Bibcode:2002AJ....123.2002H. S2CID 17735847. arXiv:astro-ph/0112496 . doi:10.1086/339315.
^ Table 1, Sion Edward M. The white dwarfs within 20 parsecs of the sun: kinematics and statistics. The Astronomical Journal. 2009, 138 (6): 1681–1689. Bibcode:2009AJ....138.1681S. S2CID 119284418. arXiv:0910.1288 . doi:10.1088/0004-6256/138/6/1681.
^ Eggen, O. J.; Greenstein, J. L. Spectra, colors, luminosities, and motions of the white dwarfs. Astrophysical Journal. 1965, 141: 83–108. Bibcode:1965ApJ...141...83E. doi:10.1086/148091. — see table 5.
^ Bell, R. A. Observations of some southern white dwarfs. The Observatory. 1962, 82: 68–71. Bibcode:1962Obs....82...68B.
^ Kawaler, S.; Dahlstrom, M. White Dwarf Stars. American Scientist. 2000, 88 (6): 498 [2007-07-19]. Bibcode:2000AmSci..88..498K. S2CID 227226657. doi:10.1511/2000.6.498. （原始内容存档于April 18, 2005）.
^ Burleigh, M. R.; Clarke, F. J.; Hodgkin, S. T. Imaging planets around nearby white dwarfs. Monthly Notices of the Royal Astronomical Society. April 2002, 331 (4): L41–L45. Bibcode:2002MNRAS.331L..41B. S2CID 18383063. arXiv:astro-ph/0202194 . doi:10.1046/j.1365-8711.2002.05417.x.
^ Siess, Lionel. Computation of Isochrones. Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles. 2000 [2007-03-24]. （原始内容存档于2011-05-05）.
^ Jao, Wei-Chun; Henry, Todd J.; Subasavage, John P.; Brown, Misty A.; Ianna, Philip A.; Bartlett, Jennifer L.; Costa, Edgardo; Méndez, René A. The Solar Neighborhood. XIII. Parallax Results from the CTIOPI 0.9 Meter Program: Stars with mu >= 1.0" yr-1 (MOTION Sample). The Astronomical Journal. 2005, 129 (4): 1954–1967. Bibcode:2005AJ....129.1954J. S2CID 16164903. arXiv:astro-ph/0502167 . doi:10.1086/428489.
^ Burleigh, Matthew R.; Clarke, F.J.; Hodgkin, S.T. Imaging Planets around Nearby White Dwarfs. Monthly Notices of the Royal Astronomical Society. 2002, 331 (4): L41–L45. Bibcode:2002MNRAS.331L..41B. S2CID 18383063. arXiv:astro-ph/0202194 . doi:10.1046/j.1365-8711.2002.05417.x.

外部連結

CC 658 （页面存档备份，存于互联网档案馆）

[1] Constellation boundaries. Centre de Données astronomiques de Strasbourg. [2007-07-16]. （原始内容存档于2019-07-17）.

[SIMBAD-2] 2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 ^2.6 LAWD 37. SIMBAD. 斯特拉斯堡天文資料中心. [2007-07-16].

[wfpc2-3] 3.0 ^3.1 Daniel J. Schroeder; et al. A Search for Faint Companions to Nearby Stars Using the Wide Field Planetary Camera 2. The Astronomical Journal. February 2000, 119 (2): 906–922. Bibcode:2000AJ....119..906S. doi:10.1086/301227 .

[GaiaEDR3-4] Brown, A. G. A.; et al. Gaia Early Data Release 3: Summary of the contents and survey properties. Astronomy & Astrophysics. 2021, 649: A1. Bibcode:2021A&A...649A...1G. S2CID 227254300. arXiv:2012.01533 . doi:10.1051/0004-6361/202039657 . 已忽略未知参数|collaboration= (帮助) (勘误: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.

[mcgill-5] 5.0 ^5.1 McGill, P.; Anderson, J.; Casertano, S.; Sahu, K.C., First semi-empirical test of the white dwarf mass-radius relationship using a single white dwarf via astrometric microlensing, Monthly Notices of the Royal Astronomical Society, March 2023, 520 (1): 259–280 [2023-02-08], doi:10.1093/mnras/stac3532

[brl-6] 6.0 ^6.1 ^6.2 ^6.3 Table 2, P. Bergeron; S. K. Leggett; María Teresa Ruiz. Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements. Astrophysical Journal Supplement Series. April 2001, 133 (2): 413–449. Bibcode:2001ApJS..133..413B. S2CID 15511301. arXiv:astro-ph/0011286 . doi:10.1086/320356.

[Gliese1991-7] Gliese, W.; Jahreiß, H. Gl 440. Preliminary Version of the Third Catalogue of Nearby Stars. 1991 [2023-03-20]. （原始内容存档于2016-03-04）.

[van_Leeuwen2007-8] Perryman; et al. HIP 57367. The Hipparcos and Tycho Catalogues. 1997 [2023-03-20]. （原始内容存档于2016-03-04）.

[Porter1930-9] Porter, J. G.; Yowell, E. J.; Smith, E. S. A catalogue of 1474 stars with proper motion exceeding four-tenths year.. Publications of the Cincinnati Observatory. 1930, 20: 1–32. Bibcode:1930PCinO..20....1P. Page 16 (Ci 20 658). （页面存档备份，存于互联网档案馆）

[Luyten1979_LHS-10] Luyten, Willem Jacob. LHS 30. LHS Catalogue, 2nd Edition. 1979 [2023-03-20]. （原始内容存档于2016-03-04）.

[Luyten1979_NLTT-11] Luyten, Willem Jacob. NLTT 28447. NLTT Catalogue. 1979 [2023-03-20]. （原始内容存档于2016-03-04）.

[van_Altena1995-12] Van Altena W. F.; Lee J. T.; Hoffleit E. D. GCTP 2716. The General Catalogue of Trigonometric Stellar Parallaxes Fourth. 1995 [2023-03-20]. （原始内容存档于2016-03-04）.

[Perryman1997_tyc-13] Perryman; et al. HIP 57367. The Hipparcos and Tycho Catalogues. 1997 [2023-03-20]. （原始内容存档于2016-03-04）.

[Hog2000-14] Hog; et al. TYC 8981-4417-1. The Tycho-2 Catalogue. 2000 [2023-03-20]. （原始内容存档于2016-03-04）.

[15] Lawd 37. [2023-03-20]. （原始内容存档于2023-03-21）.

[16] Henry, Todd J.; Walkowicz, Lucianne M.; Barto, Todd C.; Golimowski, David A. The Solar Neighborhood. VI. New Southern Nearby Stars Identified by Optical Spectroscopy. The Astronomical Journal. April 2002, 123 (4): 2002–2009. Bibcode:2002AJ....123.2002H. S2CID 17735847. arXiv:astro-ph/0112496 . doi:10.1086/339315.

[17] Table 1, Sion Edward M. The white dwarfs within 20 parsecs of the sun: kinematics and statistics. The Astronomical Journal. 2009, 138 (6): 1681–1689. Bibcode:2009AJ....138.1681S. S2CID 119284418. arXiv:0910.1288 . doi:10.1088/0004-6256/138/6/1681.

[18] Eggen, O. J.; Greenstein, J. L. Spectra, colors, luminosities, and motions of the white dwarfs. Astrophysical Journal. 1965, 141: 83–108. Bibcode:1965ApJ...141...83E. doi:10.1086/148091. — see table 5.

[19] Bell, R. A. Observations of some southern white dwarfs. The Observatory. 1962, 82: 68–71. Bibcode:1962Obs....82...68B.

[20] Kawaler, S.; Dahlstrom, M. White Dwarf Stars. American Scientist. 2000, 88 (6): 498 [2007-07-19]. Bibcode:2000AmSci..88..498K. S2CID 227226657. doi:10.1511/2000.6.498. （原始内容存档于April 18, 2005）.

[burleigh-21] Burleigh, M. R.; Clarke, F. J.; Hodgkin, S. T. Imaging planets around nearby white dwarfs. Monthly Notices of the Royal Astronomical Society. April 2002, 331 (4): L41–L45. Bibcode:2002MNRAS.331L..41B. S2CID 18383063. arXiv:astro-ph/0202194 . doi:10.1046/j.1365-8711.2002.05417.x.

[22] Siess, Lionel. Computation of Isochrones. Institut d'Astronomie et d'Astrophysique, Université libre de Bruxelles. 2000 [2007-03-24]. （原始内容存档于2011-05-05）.

[boom-23] Jao, Wei-Chun; Henry, Todd J.; Subasavage, John P.; Brown, Misty A.; Ianna, Philip A.; Bartlett, Jennifer L.; Costa, Edgardo; Méndez, René A. The Solar Neighborhood. XIII. Parallax Results from the CTIOPI 0.9 Meter Program: Stars with mu >= 1.0" yr-1 (MOTION Sample). The Astronomical Journal. 2005, 129 (4): 1954–1967. Bibcode:2005AJ....129.1954J. S2CID 16164903. arXiv:astro-ph/0502167 . doi:10.1086/428489.

[burleigh02-24] Burleigh, Matthew R.; Clarke, F.J.; Hodgkin, S.T. Imaging Planets around Nearby White Dwarfs. Monthly Notices of the Royal Astronomical Society. 2002, 331 (4): L41–L45. Bibcode:2002MNRAS.331L..41B. S2CID 18383063. arXiv:astro-ph/0202194 . doi:10.1046/j.1365-8711.2002.05417.x.

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觀測資料曆元 J2000.0 (ICRS)
星座	苍蝇座^[1]
星官
赤經	11^h 45^m 42.9205^s^[2]
赤緯	−64° 50′ 29.459″^[2]
視星等（V）	11.50^[2]
特性
光谱分类	DQ6^[3]
U−B 色指数	-0.59^[2]
B−V 色指数	+0.19^[2]
天体测定

自行 (μ)	赤经：2665.25^[2] mas/yr 赤纬：-346.19^[2] mas/yr
视差 (π)	215.6753 ± 0.0181^[4] mas
距离	15.123 ± 0.001 ly (4.6366 ± 0.0004 pc)

詳細資料

質量	0.56 ± 0.08^[5] M_☉
半徑	0.01 R_☉
表面重力 (log g)	8.27 ± 0.05^[6]
亮度	0.0005^[6] L_☉
溫度	8,500 ± 300^[6] K
年齡	(白矮星年齡)^[6] 1.44 Gyr

其他命名
GJ 440^[7]、HIP 57367^[8]、BPM 7108、Ci 20 658^[9]、EG GR 82、L 145-141、LAWD 37、LHS 43^[10]、LP 145-141、LPM 396、LTT 4364、NLTT 28447^[11]、PLX 2716^[12]、PM 11429-6434、WD 1142-645、TYC 8981-4417-1^[13]^[14]、GSC 08981-04418、2MASS J11454297-6450297
參考資料庫
SIMBAD	资料
LP 145-141 GJ 440在苍蝇座的位置