ADS 7251

ADS 7251是一個位於大熊座的雙星系統，距離太陽有6.33秒差距(20.66光年）。

ADS 7251

觀測數據 曆元 J2000      分點 J2000
星座	大熊座
ADS 7251 A
赤經	09h 14m 22.7749s[1]
赤緯	52° 41′ 11.792″[1]
視星等 (V)	7.64[2]
ADS 7251 B
赤經	09h 14m 24.6828s[3]
赤緯	52h 41m 10.902s[3]
視星等 (V)	7.70[2]
特性
光譜分類	M0V[4]
視星等 (B)	9.05[2]
視星等 (G)	6.976[1]
視星等 (J)	4.89[a][5]
視星等 (H)	3.987[a][5]
視星等 (K)	3.99[a][5]
B−V 色指數	+1.41[6]
J−H 色指數	+0.90[b]
J−K 色指數	+0.90[b]
天體測定
ADS 7251 A (HD 79210)
徑向速度 (Rv)	7001112449999999999♠11.245±0.0007[1] km/s
自行 (μ)	赤經：2996845421300000000♠−1,545.787±0.018[1] mas/yr 赤緯：2997430947000000000♠−569.053±0.018[1] mas/yr
視差 (π)	157.8879 ± 0.0197[1] mas
距離	20.657 ± 0.003 ly (6.3336 ± 0.0008 pc)
絕對星等 (MV)	8.637[7]
ADS 7251 B
徑向速度 (Rv)	7001121039999999999♠12.104±0.0008[3] km/s
自行 (μ)	赤經：2996842695999999999♠−1,573.040±0.018[3] mas/yr 赤緯：2997340094000000000♠−659.906±0.018[3] mas/yr
視差 (π)	157.8825 ± 0.0211[3] mas
距離	20.658 ± 0.003 ly (6.3338 ± 0.0008 pc)
絕對星等 (MV)	8.712[7]
軌道[8]
繞行週期 (P)	975 yr
半長軸 (a)	16.725"
偏心率 (e)	0.28
詳細資料 [9]
A
質量	6999690000000000000♠0.69±0.07 M☉
半徑	6999580000000000000♠0.58±0.02 R☉
表面重力 (log g)	7000468000000000000♠4.68±0.07
亮度	6998789000000000000♠0.0789±0.0038 L☉
溫度	7003402400000000000♠4,024±51 K
自轉	7001163000000000000♠16.3+3.5 −1.3
自轉速度 (v sin i)	7000200000000000000♠2.0±1.2 km/s
B
質量	6999640000000000000♠0.64±0.07 M☉
半徑	6999580000000000000♠0.58±0.03 R☉
表面重力 (log g)	7000468000000000000♠4.68±0.07
亮度	6998792000000000000♠0.0792±0.0031 L☉
溫度	7003400500000000000♠4,005±51 K
自轉	7001166100000000000♠16.61±0.04
自轉速度 (v sin i)	7000229999999999999♠2.3±1.5 km/s
年齡	1–7 Gyr
Other designations
GJ 338、​ADS 7251、​WDS J09144+5241
A: BD+53°1320、​HD 79210、​HIP 45343
B: BD+53°1321、​HD 79211、​HIP 120005
參考資料庫
SIMBAD	The system
	A
	B
ADS 7251 ADS 7251在大熊座的位置

這兩顆恆星共享一個略微偏心的軌道，其半長軸為16.725″，週期為975年。^[10]

ADS 7251 A比ADS 7251 B亮0.06星等。MK光譜等級目錄將兩顆恆星列為二級標準，ADS 7251 A為M0V級，ADS 7251 B為K7V級，在具有較晚光譜類型的較亮恆星。^[4]

行星系統

ADS 7251 B也稱為Gliese 338B或 HD 79211，由一顆已知的超級地球圍繞其運行，並通過徑向速度檢測到。^[9]

ADS 7251 B (Gliese 338 B)的行星系^[11]

成員 (依恆星距離)	質量	半長軸 (AU)	軌道周期 (天)	離心率	傾角	半徑
b	10.8+1.2 − M⊕	0.142+0.005 −	24.422+0.014 −	6999110000000000000♠0.11+0.11 −0.08	—	—

註釋

1. 2MASS infrared magnitudes flagged as unreliable or upper limits
2. Calculated from 2MASS magnitudes

參考

1. 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 . 已忽略未知參數|collaboration= (幫助) (勘誤: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
2. Huang, Y.; Liu, X. -W.; Yuan, H. -B.; Xiang, M. -S.; Chen, B. -Q.; Zhang, H. -W. Empirical metallicity-dependent calibrations of effective temperature against colours for dwarfs and giants based on interferometric data. Monthly Notices of the Royal Astronomical Society. 2015, 454 (3): 2863. Bibcode:2015MNRAS.454.2863H. S2CID 118487917. arXiv:1508.06080 . doi:10.1093/mnras/stv1991.
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 . 已忽略未知參數|collaboration= (幫助) (勘誤: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
4. Kirkpatrick, J. D.; et al. A standard stellar spectral sequence in the red/near-infrared - Classes K5 to M9. Astrophysical Journal Supplement Series. 1991, 77: 417. Bibcode:1991ApJS...77..417K. doi:10.1086/191611.
5. Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003). CDS/ADC Collection of Electronic Catalogues. 2003, 2246: II/246 [2023-03-22]. Bibcode:2003yCat.2246....0C. （原始內容存檔於2021-04-21）.
6. Bobylev, V. V.; Goncharov, G. A.; Bajkova, A. T. VizieR Online Data Catalog: Orion Spiral Arm CAtalogue (OSACA) (Bobylev+, 2006). VizieR On-line Data Catalog. 2007. Bibcode:2007yCat..90830821B.
7. Houdebine, Éric R.; Mullan, D. J.; Doyle, J. G.; de la Vieuville, Geoffroy; Butler, C. J.; Paletou, F. The Mass-Activity Relationships in M and K Dwarfs. I. Stellar Parameters of Our Sample of M and K Dwarfs. The Astronomical Journal. 2019, 158 (2): 56. Bibcode:2019AJ....158...56H. S2CID 159041104. arXiv:1905.07921 . doi:10.3847/1538-3881/ab23fe.
8. Malkov, O. Yu.; et al. Dynamical Masses of a Selected Sample of Orbital Binaries. Astronomy & Astrophysics. 2012, 546: 5. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774 . A69.
9. González-Álvarez, E.; Osorio, M. R. Zapatero; Caballero, J. A.; Sanz-Forcada, J.; Béjar, V. J. S.; González-Cuesta, L.; Dreizler, S.; Bauer, F. F.; Rodríguez, E.; Tal-Or, L.; Zechmeister, M. The CARMENES search for exoplanets around M dwarfs. A super-Earth planet orbiting HD 79211 (GJ 338 B). Astronomy & Astrophysics. May 2020, 637: A93. Bibcode:2020A&A...637A..93G. ISSN 0004-6361. arXiv:2003.13052 . doi:10.1051/0004-6361/201937050 .
10. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog. The Astronomical Journal. 2001, 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920 .
11. Ditomasso, Victoria; et al, Independent Validation of the Temperate Super-Earth HD 79211 b using HARPS-N, The Astronomical Journal, 2023, 165 (2): 38, Bibcode:2023AJ....165...38D, S2CID 253098124, arXiv:2210.12211 , doi:10.3847/1538-3881/ac9ccd