金牛座V773

金牛座V773是在黃道星座金牛座的年輕聚星，位於它的中心區域^[7]。這是一顆金牛T星型變星，其視星等範圍從10.59到10.95^[4]，它太黯淡了，因此肉眼看不見。根據各種估計，該系統距離太陽約433光年。它位於林茲1495（Lynds 1495）暗星雲的附近^[7]。

Aa

Period = 51.1 d

Ab

Period = 26.5 yr

B(ab)

Period = 624 yr

C

軌道層次

金牛座V773

上圖顯示「TESS」觀測的 金牛座V773的光變曲線[1]。 下圖改編自肯沃西（Kenworthy） 等人[2]，顯示出2010年觀測的食。
觀測資料 曆元 J2000
星座	金牛座
星官
赤經	04h 14m 12.926s[3]
赤緯	28° 12′ 12.36″[3]
視星等（V）	7001105900000000000♠10.59 to 10.95[4]
特性
光谱分类	K3Ve (Li)[5]
变星类型	獵戶型變星 + BY Dra[4]
天体测定
自行 (μ)	赤经：6.540 mas/yr 赤纬：−27.792 mas/yr
视差 (π)	8.3261 ± 0.1313 mas
距离	433.1 ± 7.5 ly (132.8+2.3 − pc)
軌道[2]
主星	金牛座V773 AB
伴星	金牛座V773 C
繞行週期 (P)	7002624000000000000♠624+83 −52 yr
半長軸 (a)	6994491116258963961♠1,013+93 −74 mas
偏心率 (e)	6999400000000000000♠0.40+0.04 −0.05
倾斜角 (i)	97.3+0.6 −°
升交点黃經 (Ω)	104.6+1.3 −°
近心点 曆元 (T)	7003174000000000000♠1,740+26 −40
近心點幅角 (ω) (secondary)	107.8+4.5 −°
軌道[2]
主星	金牛座V773 A
伴星	金牛座V773 B
繞行週期 (P)	26.50+0.07 − yr
半長軸 (a)	6993570625702665925♠117.7±0.86 mas
偏心率 (e)	0.104+0.009 −
倾斜角 (i)	69.25+0.40 −°
升交点黃經 (Ω)	290.54+0.40 −°
近心点 曆元 (T)	2,010.11+0.12 −
近心點幅角 (ω) (secondary)	266.0+1.5 −°
半振幅 (K1) (primary)	6.50+0.50 −[6] km/s
軌道[7]
主星	金牛座V773 Aa
伴星	金牛座V773 Ab
繞行週期 (P)	7006441532512000000♠51.1033±0.0018 d
半長軸 (a)	6992136184163023668♠2.809±0.033 mas
偏心率 (e)	0.2713+0.0066 −
倾斜角 (i)	68.5+1.6 −°
升交点黃經 (Ω)	62.4+1.1 −°
近心点 曆元 (T)	7004530597500000000♠53,059.75±0.28 MJD
近心點幅角 (ω) (secondary)	5.6+2.2 −°
半振幅 (K1) (primary)	35.72+0.46 − km/s
半振幅 (K2) (secondary)	42.9+1.3 − km/s
詳細資料
Aa
質量	1.55+0.11 −[7] M☉
半徑	2.22[8] R☉
表面重力 (log g)	3.93[8]
亮度	2.56[8] L☉
溫度	4,900[8] K
年齡	3+1 −[2] Myr
Ab
質量	1.293+0.068 −[7] M☉
半徑	1.74[8] R☉
表面重力 (log g)	4.08[8]
亮度	1.37[8] L☉
溫度	4,740[8] K
其他命名
V773 Tau、​HD 283447、​HIP 19762、​WDS J04142+2813A[9]
參考資料庫
SIMBAD	资料

這個系統在1974年被呂德格倫（a.E.Rydgren）及其同事確認為金牛T星^[10]。1983年，從這個來源探測到無線電發射^[11]。在1993年，它被發現是一顆雙星，角距離約為6993727220521664305♠150 mas：這兩個成員被指定為A和B。成員A被發現是具有51天軌道週期的雙線光譜聯星。在2003年，發現該系統的第三顆成員，成員C^[7]，與成員A的角距離為6994124112302364041♠256 mas。

A–B對的軌道解為B成員提供了出乎意料的高動態質量（英语：dynamic mass）7000269000000000000♠2.69±0.67 太陽質量，這表明它也可能是一個聯星系統^[6]。一顆質量如此之大的恆星光度是太陽的17倍，這與觀測到的光學光度不一致。對成員B的光度測定表明，它正沿著視線從塵埃中經歷消光。該成員在K波段是可變的，這與軌道上的塵埃團或雲一致^[2]。

2010年，在金牛座V773系統中觀測到了一次擴展的星食。這被解釋為成員B的環雙星盤從成員A的前面經過。星食遮蔽了成員A 70%的發射，並持續了150天^[2]。

參考資料

1. MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, [8 December 2021], （原始内容存档于2023-03-27）.
2. Kenworthy, M. A.; et al, Eclipse of the V773 Tau B circumbinary disc, Astronomy & Astrophysics, October 2022, 666: A61, Bibcode:2022A&A...666A..61K, S2CID 250451004, arXiv:2207.05575 , doi:10.1051/0004-6361/202243441, A61.
3. 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.
4. Samus, N. N.; et al, General Catalogue of Variable Stars, Astronomy Reports, 5.1, 2017, 61 (1): 80–88, Bibcode:2017ARep...61...80S, S2CID 125853869, doi:10.1134/S1063772917010085.
5. Herbig, G. H., Radial velocities and spectral types of T Tauri stars, Astrophysical Journal, 1977, 214: 747–758, Bibcode:1977ApJ...214..747H, doi:10.1086/155304 .
6. Boden, Andrew F.; et al, A Surprising Dynamical Mass for V773 Tau B, The Astrophysical Journal, March 2012, 747 (1): 17, Bibcode:2012ApJ...747...17B, S2CID 118997621, arXiv:1112.1018 , doi:10.1088/0004-637X/747/1/17, 17.
7. Torres, Rosa M.; et al, VLBA Determination of the Distance to nearby Star-forming Regions. V. Dynamical Mass, Distance, and Radio Structure of V773 Tau A, The Astrophysical Journal, March 2012, 747 (1): 18, Bibcode:2012ApJ...747...18T, S2CID 494696, arXiv:1112.0114 , doi:10.1088/0004-637X/747/1/18, 18.
8. Boden, Andrew F.; et al, Dynamical Masses for Pre-Main-Sequence Stars: A Preliminary Physical Orbit for V773 Tau A, The Astrophysical Journal, December 2007, 670 (2): 1214–1224, Bibcode:2007ApJ...670.1214B, S2CID 40241514, arXiv:0706.2376 , doi:10.1086/521296.
9. HD 283447. SIMBAD. 斯特拉斯堡天文資料中心.
10. Rydgren, A. E.; et al, The nature of the objects of Joy: a study of the T Tauri phenomenon., Astrophysical Journal Supplement Series, March 1976, 30: 307–336, Bibcode:1976ApJS...30..307R, doi:10.1086/190364. See notes about HD 283447.
11. Kutner, M. L.; et al, Detection of 6 CM radio emission from late-type PMS stars with weak chromospheric emission, Astronomical Journal, October 1986, 92: 895–897, Bibcode:1986AJ.....92..895K, doi:10.1086/114223 .

進階讀物

• Umemoto, T.; et al, Hagiwara, Yoshiaki; et al , 编, Detection of a Radio Flare at Millimeter-Wavelengths from the X-ray T Tauri Star V773 Tau, Approaching Micro-Arcsecond Resolution with VSOP-2, proceedings of the conference held 3–7 December 2007, at ISAS/JAXA, Sagamihara, Kanagawa, Japan, Astrophysics and Technologies ASP Conference Series 402, August 2009, 402: 400, Bibcode:2009ASPC..402..400U.
• Massi, M.; et al, Interacting coronae of two T Tauri stars: first observational evidence for solar-like helmet streamers, Astronomy and Astrophysics, March 2008, 480 (2): 489–494, Bibcode:2008A&A...480..489M, S2CID 11380885, arXiv:0712.0718 , doi:10.1051/0004-6361:20078637.
• Massi, M.; et al, Synchrotron emission from the T Tauri binary system V773 Tauri A, Astronomy and Astrophysics, July 2006, 453 (3): 959–964, Bibcode:2006A&A...453..959M, S2CID 14134438, arXiv:astro-ph/0604124 , doi:10.1051/0004-6361:20053535.
• Duchêne, G.; et al, No Fossil Disk in the T Tauri Multiple System V773 Tauri, The Astrophysical Journal, July 2003, 592 (1): 288–298, Bibcode:2003ApJ...592..288D, S2CID 119094313, arXiv:astro-ph/0303648 , doi:10.1086/375624.
• Tamazian, Vakhtang S.; et al, Preliminary Orbits and System Masses for Five Binary T Tauri Stars, The Astrophysical Journal, October 2002, 578 (2): 925–934, Bibcode:2002ApJ...578..925T, S2CID 123360722, doi:10.1086/342621.
• Massi, M.; et al, Periodic radio flaring on the T Tauri star V 773 Tauri, Astronomy and Astrophysics, January 2002, 382: 152–156, Bibcode:2002A&A...382..152M, S2CID 56413068, doi:10.1051/0004-6361:20011585.
• Tsuboi, Yohko; et al, ASCA Detection of a Superhot 100 Million K X-Ray Flare on the Weak-Lined T Tauri Star V773 Tauri, The Astrophysical Journal, August 1998, 503 (2): 894–901, Bibcode:1998ApJ...503..894T, S2CID 121483342, doi:10.1086/306024 .
• Skinner, Stephen L.; et al, ASCA Observations of the Barnard 209 Dark Cloud and an Intense X-Ray Flare on V773 Tauri, The Astrophysical Journal, September 1997, 486 (2): 886–902, Bibcode:1997ApJ...486..886S, S2CID 123108722, doi:10.1086/304561, hdl:2060/19980076126 .
• Skinner, S. L., Time-Resolved X-ray Spectroscopy of the Weak-lined T Tauri Star V773 Tau, Bulletin of the American Astronomical Society, May 1996, 28: 884, Bibcode:1996AAS...188.4008S.
• Welty, Alan D., Discovery of a Pre-Main-Sequence Spectrscopic Binary: V773 Tauri, Astronomical Journal, August 1995, 110: 776, Bibcode:1995AJ....110..776W, doi:10.1086/117562.