上輔

**上輔（天龍座λ）**
	上輔的位置（紅圈）
觀測資料; 曆元 J2000.0
星座	天龍座
星官	紫微右垣（紫微垣）
赤經	11h 31m 24.22075s
赤緯	+69° 19′ 51.8696″
視星等（V）	+3.85
特性
光譜分類	M0III-IIIa Ca1
U−B 色指數	+1.97
B−V 色指數	+1.62
變星類型	慢不規則
天體測定
徑向速度 (Rv)	+6.58±0.30 km/s
自行 (μ)	赤經：−40.97 mas/yr ; 赤緯：−19.19 mas/yr
視差 (π)	9.79 ± 0.15 mas
距離	333 ± 5 ly ; (102 ± 2 pc)
絕對星等 (MV)	−1.14±0.033
詳細資料
質量	1.7 M☉
半徑	71 R☉
表面重力 (log g)	1.10±0.05
亮度	834 L☉
溫度	3,958 K
其他命名
	λ Dra、1 Draconis、 BD−70° 665、FK5 433、HD 100029、HIP 56211、HR 4434、 SAO 15532
參考資料庫
SIMBAD	資料

上輔（Lambda Draconis、λ Draconis，縮寫為Lam Dra、λ Dra），也稱為Giausar^[12]，位於拱極星座天龍座內，是一顆單獨^[13]、呈現橘紅色^[14]的恆星。它的視星等為 +3.8等，可以用裸眼直接看見^[2]。依據從地球上測量到的視差9,79mas ^[1]，這顆恆星距離太陽約333光年。

這是一顆已經演化至漸近巨星分支的紅巨星^[15]，在分類上是MOIII-IIIaCa1^[3]，並被懷疑是顆週期大約1,100天的慢不規則變星^[4]。在修正臨邊昏暗之後，測量所得的角直徑為7000643000000000000♠6.43±0.07 mas.^[16]。在前述的估計距離上，它的真實半徑大約是太陽半徑的53倍^[8]，質量是太陽質量的1.7倍^[7]，來自有效溫度3,958K的光球亮度是太陽亮度的834倍^[10]。

名稱

同名物體

美國海軍巨爵級貨船（英語：Crater class cargo ship）USS Giansar (AK-111)（英語：USS Giansar (AK-111)）以這顆恆星命名。

參考資料

^ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752  , doi:10.1051/0004-6361:20078357.
^ ^2.0 ^2.1 ^2.2 ^2.3 Johnson, H. L.; et al, UBVRIJKL photometry of the bright stars, Communications of the Lunar and Planetary Laboratory, 1966, 4 (99), Bibcode:1966CoLPL...4...99J.
^ ^3.0 ^3.1 Keenan, Philip C.; McNeil, Raymond C., The Perkins catalog of revised MK types for the cooler stars, Astrophysical Journal Supplement Series, 1989, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
^ ^4.0 ^4.1 Samus, N. N.; Durlevich, O. V.; et al, Combined General Catalogue of Variable Stars (GCVS4.2), 2007 [2016-09-30], （原始內容存檔於2018-10-10）.
^ Famaey, B.; et al, Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations, Astronomy and Astrophysics, 2009, 498 (2): 627–640, Bibcode:2009A&A...498..627F, arXiv:0901.0934  , doi:10.1051/0004-6361/200810698.
^ Park, Sunkyung; et al, Wilson-Bappu Effect: Extended to Surface Gravity, The Astronomical Journal, 2013, 146 (4): 73, Bibcode:2013AJ....146...73P, arXiv:1307.0592  , doi:10.1088/0004-6256/146/4/73.
^ ^7.0 ^7.1 Gondoin, P., Evolution of X-ray activity and rotation on G-K giants, Astronomy and Astrophysics, December 1999, 352: 217–227, Bibcode:1999A&A...352..217G.
^ ^8.0 ^8.1 Lang, Kenneth R., Astrophysical formulae, Astronomy and astrophysics library 1 3rd, Birkhäuser, 2006 [2019-01-20], ISBN 3-540-29692-1, （原始內容存檔於2019-05-20）. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(102.1\cdot 6.43\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 141.2\cdot R_{\bigodot }\end{aligned}}$
^ Takagi, Yuhei; et al, Age Determinations of Early-M Type Pre-Main Sequence Stars Using a High-Resolution Near-Infrared Spectroscopic Method, Publications of the Astronomical Society of Japan, June 2011, 63 (3): 677–684, Bibcode:2011PASJ...63..677T, doi:10.1093/pasj/63.3.677.
^ ^10.0 ^10.1 ^10.2 McDonald, I.; et al, Fundamental parameters and infrared excesses of Hipparcos stars, Monthly Notices of the Royal Astronomical Society, 2012, 427: 343, Bibcode:2012MNRAS.427..343M, arXiv:1208.2037  , doi:10.1111/j.1365-2966.2012.21873.x.
^ lam Dra. SIMBAD. 斯特拉斯堡天文資料中心. [2017-05-28].
^ Naming Stars. IAU.org. [2017-12-16]. （原始內容存檔於2020-04-11）.
^ Eggleton, P. P.; Tokovinin, A. A., A catalogue of multiplicity among bright stellar systems, Monthly Notices of the Royal Astronomical Society, September 2008, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878  , doi:10.1111/j.1365-2966.2008.13596.x.
^ Moore, Patrick, The Observer’s Year: 366 Nights of the Universe, The Patrick Moore Practical Astronomy Series, Springer Science & Business Media: 285, 2013, ISBN 1447136136
^ Eggen, O. J. Asymptotic giant branch stars near the sun. The Astronomical Journal. 1992, 104: 275. Bibcode:1992AJ....104..275E. doi:10.1086/116239.
^ Richichi, A.; et al, CHARM2: An updated Catalog of High Angular Resolution Measurements, Astronomy and Astrophysics, February 2005, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.

引用錯誤：在<references>標籤中name屬性為「Kaler」的參考文獻沒有在文中使用

引用錯誤：在<references>標籤中name屬性為「Allen1963」的參考文獻沒有在文中使用

[vanLeeuwen2007-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752  , doi:10.1051/0004-6361:20078357.

[Johnson1966-2] 2.0 ^2.1 ^2.2 ^2.3 Johnson, H. L.; et al, UBVRIJKL photometry of the bright stars, Communications of the Lunar and Planetary Laboratory, 1966, 4 (99), Bibcode:1966CoLPL...4...99J.

[perkins1989-3] 3.0 ^3.1 Keenan, Philip C.; McNeil, Raymond C., The Perkins catalog of revised MK types for the cooler stars, Astrophysical Journal Supplement Series, 1989, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.

[Samus2007-4] 4.0 ^4.1 Samus, N. N.; Durlevich, O. V.; et al, Combined General Catalogue of Variable Stars (GCVS4.2), 2007 [2016-09-30], （原始內容存檔於2018-10-10）.

[Famaey2009-5] Famaey, B.; et al, Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations, Astronomy and Astrophysics, 2009, 498 (2): 627–640, Bibcode:2009A&A...498..627F, arXiv:0901.0934  , doi:10.1051/0004-6361/200810698.

[park2013-6] Park, Sunkyung; et al, Wilson-Bappu Effect: Extended to Surface Gravity, The Astronomical Journal, 2013, 146 (4): 73, Bibcode:2013AJ....146...73P, arXiv:1307.0592  , doi:10.1088/0004-6256/146/4/73.

[Gondoin1999-7] 7.0 ^7.1 Gondoin, P., Evolution of X-ray activity and rotation on G-K giants, Astronomy and Astrophysics, December 1999, 352: 217–227, Bibcode:1999A&A...352..217G.

[lang2006-8] 8.0 ^8.1 Lang, Kenneth R., Astrophysical formulae, Astronomy and astrophysics library 1 3rd, Birkhäuser, 2006 [2019-01-20], ISBN 3-540-29692-1, （原始內容存檔於2019-05-20）. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(102.1\cdot 6.43\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 141.2\cdot R_{\bigodot }\end{aligned}}$

[Tagaki2011-9] Takagi, Yuhei; et al, Age Determinations of Early-M Type Pre-Main Sequence Stars Using a High-Resolution Near-Infrared Spectroscopic Method, Publications of the Astronomical Society of Japan, June 2011, 63 (3): 677–684, Bibcode:2011PASJ...63..677T, doi:10.1093/pasj/63.3.677.

[mcdonald2012-10] 10.0 ^10.1 ^10.2 McDonald, I.; et al, Fundamental parameters and infrared excesses of Hipparcos stars, Monthly Notices of the Royal Astronomical Society, 2012, 427: 343, Bibcode:2012MNRAS.427..343M, arXiv:1208.2037  , doi:10.1111/j.1365-2966.2012.21873.x.

[SIMBAD-11] Dra. SIMBAD. 斯特拉斯堡天文資料中心. [2017-05-28].

[IAU-LSN-12] Naming Stars. IAU.org. [2017-12-16]. （原始內容存檔於2020-04-11）.

[Eggleton2008-13] Eggleton, P. P.; Tokovinin, A. A., A catalogue of multiplicity among bright stellar systems, Monthly Notices of the Royal Astronomical Society, September 2008, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878  , doi:10.1111/j.1365-2966.2008.13596.x.

[Moore2013-14] Moore, Patrick, The Observer’s Year: 366 Nights of the Universe, The Patrick Moore Practical Astronomy Series, Springer Science & Business Media: 285, 2013, ISBN 1447136136

[eggen1992-15] Eggen, O. J. Asymptotic giant branch stars near the sun. The Astronomical Journal. 1992, 104: 275. Bibcode:1992AJ....104..275E. doi:10.1086/116239.

[Richichi2005-16] Richichi, A.; et al, CHARM2: An updated Catalog of High Angular Resolution Measurements, Astronomy and Astrophysics, February 2005, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.

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[16]

觀測資料曆元 J2000.0
上輔的位置（紅圈）
星座	天龍座
星官	紫微右垣（紫微垣）
赤經	11^h 31^m 24.22075^s^[1]
赤緯	+69° 19′ 51.8696″^[1]
視星等（V）	+3.85^[2]
特性
光譜分類	M0III-IIIa Ca1^[3]
U−B 色指數	+1.97^[2]
B−V 色指數	+1.62^[2]
變星類型	慢不規則^[4]
天體測定

徑向速度 (R_v)	7000658000000000000♠+6.58±0.30^[5] km/s
自行 (μ)	赤經：−40.97^[1] mas/yr 赤緯：−19.19^[1] mas/yr
視差 (π)	9.79 ± 0.15^[1] mas
距離	333 ± 5 ly (102 ± 2 pc)
絕對星等 (M_V)	2999886000000000000♠−1.14±0.033^[6]

詳細資料

質量	1.7^[7] M_☉
半徑	71^[8] R_☉
表面重力 (log g)	7000110000000000000♠1.10±0.05^[9]
亮度	834^[10] L_☉
溫度	3,958^[10] K

其他命名
λ Dra、1 Draconis、 BD−70° 665、FK5 433、HD 100029、HIP 56211、HR 4434、 SAO 15532^[11]
參考資料庫
SIMBAD	資料