白羊座UX
白羊座UX是在北天的黃道星座白羊座的一個三合星系統。基於來自蓋亞衛星的視差測量，它距離太陽系大約165光年。主星，白羊座UX Aa，是一顆RS CVn型變星。這顆恆星的光度變化被認為是由於冷星斑和溫暖的耀斑組合，與恆星大氣層的基態溫度相對照。這種變化似乎是週期性，週期為8-9年[6]。這顆恆星的亮度從視星等6.35到6.71不等，這意味著在理想的黑暗天空條件下，肉眼可能會間歇性地看到它[3]。
| 觀測資料 曆元 J2000 | |
|---|---|
| 星座 | 白羊座 |
| 星官 | |
| 赤經 | 03h 26m 35.37568s[2] |
| 赤緯 | +28° 42′ 54.2264″[2] |
| 視星等（V） | 6.35 - 6.71[3] |
| 特性 | |
| 光譜分類 | G5IV[4] |
| U−B 色指數 | 0.43[5] |
| B−V 色指數 | 0.90[5] |
| 變星類型 | RS CVn[6] |
| 天體測定 | |
| 徑向速度 (Rv) | +26.53[7] km/s |
| 自行 (μ) | 赤經：+46.794[2] mas/yr 赤緯：−102.876[2] mas/yr |
| 視差 (π) | 19.7836 ± 0.1264[2] mas |
| 距離 | 165 ± 1 ly (50.5 ± 0.3 pc) |
| 絕對星等 (MV) | 2.91[8] |
| 軌道[9] | |
| 主星 | Aa |
| 伴星 | Ab |
| 繞行週期 (P) | 6.437888±0.000007 d |
| 半長軸 (a) | 1.750±0.01 mas |
| 偏心率 (e) | 0 (fixed) |
| 傾斜角 (i) | 125.0±0.5° |
| 升交點黃經 (Ω) | 113.4±0.4° |
| 近心點 曆元 (T) | 2456238.134 ± 0.002 HJD |
| 近心點幅角 (ω) (secondary) | 90（確定的）° |
| 軌道[10] | |
| 主星 | A |
| 伴星 | B |
| 繞行週期 (P) | 111.02 yr |
| 半長軸 (a) | 648.0±0.8 mas |
| 偏心率 (e) | 0.77±0.01 |
| 傾斜角 (i) | 93.3±0.6° |
| 升交點黃經 (Ω) | 58.9±0.5° |
| 近心點 曆元 (T) | 2451664.9±34.3 HJD |
| 近心點幅角 (ω) (secondary) | 274.9±0.8° |
| 詳細資料 [9] | |
| 白羊座UX Aa | |
| 質量 | 1.30±0.06 M☉ |
| 半徑 | 5.6±0.1 R☉ |
| 表面重力 (log g) | 3.06±0.04 |
| 亮度 | 9.3±0.7 L☉ |
| 溫度 | 4,560±100 K |
| 自轉 | 6.44 d[4] |
| 白羊座UX Ab | |
| 質量 | 1.14±0.06 M☉ |
| 半徑 | 1.6±0.2 R☉ |
| 表面重力 (log g) | 4.09±0.16 |
| 亮度 | 2.34±0.28 L☉ |
| 溫度 | 5,670±100 K |
| 白羊座UX B | |
| 質量 | 0.75 M☉ |
| 半徑 | 0.8±0.1 R☉ |
| 表面重力 (log g) | 4.51±0.13 |
| 亮度 | 0.38±0.08 L☉ |
| 溫度 | 4,930±100 K |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | 資料 |
| ARICNS | 資料 |
一顆更遠的伴星，成員C，有著共同自行，並且處於相同的距離上[11]。它是另一顆冷矮星，估計光譜等級為K2。任何一種估計的軌道都超過10萬年[12]。
參考資料
- ^ Ulvås, V. Aarum; Henry, G. W. BV photometry of UX Ari in the period 1987–2002. Astronomy & Astrophysics. May 2003, 402 (3): 1033–1041. Bibcode:2003A&A...402.1033A. doi:10.1051/0004-6361:20030304
.
- ^ 2.0 2.1 2.2 2.3 2.4 Vallenari, A.; et al. Gaia Data Release 3. Summary of the content and survey properties. Astronomy & Astrophysics. 2022. arXiv:2208.00211 . doi:10.1051/0004-6361/202243940 . 已忽略未知參數
|collaboration=(幫助) Gaia DR3 record for this source at VizieR. - ^ 3.0 3.1 UX Ari. The International Variable Star Index. AAVSO. [28 October 2021]. （原始內容存檔於2021-10-29）.
- ^ 4.0 4.1 Strassmeier, Klaus G. Starspots. The Astronomy and Astrophysics Review. September 2009, 17 (3): 251–308. Bibcode:2009A&ARv..17..251S. doi:10.1007/s00159-009-0020-6 .
- ^ 5.0 5.1 Guetter, H. H.; Hewitt, A. V. Photoelectric UBV photometry for 317 PZT and VZT stars. Publications of the Astronomical Society of the Pacific. June 1984, 96: 441–443. Bibcode:1984PASP...96..441G. doi:10.1086/131362 .
- ^ 6.0 6.1 Alekseev, I. Yu. Three-Component Model of Spottedness in the Classical RS CVn System UX Ari. Astrophysics. September 2014, 57 (3): 344–351. Bibcode:2014Ap.....57..344A. S2CID 119963417. doi:10.1007/s10511-014-9339-4.
- ^ Karataș, Yüksel; Bilir, Selçuk; Eker, Zeki; Demircan, Osman; Liebert, James; Hawley, Suzanne L.; Fraser, Oliver J.; Covey, Kevin R.; Lowrance, Patrick; Kirkpatrick, J. Davy; Burgasser, Adam J. Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution. Monthly Notices of the Royal Astronomical Society. 2004, 349 (3): 1069–1092. Bibcode:2004MNRAS.349.1069K. S2CID 15290475. arXiv:astro-ph/0404219 . doi:10.1111/j.1365-2966.2004.07588.x.
- ^ Anderson, E.; Francis, Ch. XHIP: An extended hipparcos compilation. Astronomy Letters. May 2012, 38 (5): 331–346. Bibcode:2012AstL...38..331A. ISSN 1063-7737. S2CID 119257644. arXiv:1108.4971 . doi:10.1134/S1063773712050015. eISSN 1562-6873.
- ^ 9.0 9.1 Hummel, C. A.; et al. Orbital Elements and Stellar Parameters of the Active Binary UX Arietis. The Astrophysical Journal. August 2017, 844 (2): 12. Bibcode:2017ApJ...844..115H. S2CID 43383613. doi:10.3847/1538-4357/aa7b87. hdl:10871/32318 . 115.
- ^ Peterson, W. M.; Mutel, R. L.; Lestrade, J. -F.; Güdel, M.; Goss, W. M. Radio Astrometry of the Triple Systems Algol and UX Arietis. The Astrophysical Journal. 2011, 737 (2): 104. Bibcode:2011ApJ...737..104P. S2CID 119229905. arXiv:1104.5005 . doi:10.1088/0004-637X/737/2/104.
- ^ Vallenari, A.; et al. Gaia Data Release 3. Summary of the content and survey properties. Astronomy & Astrophysics. 2022. arXiv:2208.00211 . doi:10.1051/0004-6361/202243940 . 已忽略未知參數
|collaboration=(幫助) Gaia DR3 record for this source at VizieR. - ^ Tokovinin, Andrei. The Updated Multiple Star Catalog. The Astrophysical Journal Supplement Series. 2018-03-01, 235 (1): 6. Bibcode:2018ApJS..235....6T. ISSN 0067-0049. S2CID 119047709. arXiv:1712.04750 . doi:10.3847/1538-4365/aaa1a5.
進階讀物
- Brinkman, Albert. High-Resolution Spectrum of UX Ari. Chandra Proposal ID #02200030. 2000: 434. Bibcode:2000cxo..prop..434B.
- Drake, Stephen. Acis/hetg Spectroscopy of the Active Binaries Algol & UX Ari. Chandra Proposal ID #01200248. 1999: 20. Bibcode:1999cxo..prop...20D.
- V. Aarum Ulvås & G. W. Henry. BV photometry of UX Ari in the period 1987-2002. Astronomy and Astrophysics. 2003.