小犬座YZ
小犬座YZ 是位於小犬座中的一顆紅色恆星。視星等為11.15[2]，肉眼無法看到它。目前，這顆恆星正以+26.5公里/秒的日心徑向速度向更遠的地方移動。[4]大約162,000年前，當它以10.2光年的距離通過近日點時，它最接近地球。[12]小犬座YZ是繪架座β移動星群的潛在成員。[13]
 小犬座YZ的光變曲線，主圖顯示了周期性的亮度變化和幾個耀斑。插圖顯示了具有擴展時間尺度的最強耀斑。 | |
| 觀測資料 曆元 J2000 | |
|---|---|
| 星座 | 小犬座 |
| 星官 | |
| 赤經 | 07h 44m 40.17230s[1] |
| 赤緯 | +03° 33′ 08.8752″[1] |
| 視星等（V） | 11.15[2] |
| 特性 | |
| 光谱分类 | M5 V[3] |
| B−V 色指数 | 1.61[2] |
| 天体测定 | |
| 徑向速度 (Rv) | +26.53±0.30[4] km/s |
| 自行 (μ) | 赤经：−347.782[1] mas/yr 赤纬：−445.702[1] mas/yr |
| 视差 (π) | 166.9769 ± 0.0343[1] mas |
| 距离 | 19.533 ± 0.004 ly (5.989 ± 0.001 pc) |
| 绝对星等 (MV) | 12.32[5] |
| 詳細資料 | |
| 質量 | 0.308[6] M☉ |
| 半徑 | 0.324[6] R☉ |
| 表面重力 (log g) | 5.0[7] |
| 亮度 | 0.012[1] L☉ |
| 溫度 | 3,125±61[8] K |
| 金属量 [Fe/H] | −0.26±0.08[8] dex |
| 自轉 | 2.8[6] days |
| 自轉速度 (v sin i) | 4.0[9] km/s |
| 年齡 | 49[10] Myr |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | 资料 |
  YZ 小犬座YZ在小犬座的位置 | |
這是一顆紅矮星，恆星分類為M5V。[3] 它也是耀星，因其恆星耀斑比太陽的耀斑更強大而得名，並且大約是木星大小的三倍。[14]
參考
- ^ 1.0 1.1 1.2 1.3 1.4 1.5 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 . 已忽略未知参数|collaboration=(帮助) Gaia DR3 record for this source at VizieR. - ^ 2.0 2.1 2.2 Astudillo-Defru, N.; et al. Magnetic activity in the HARPS M dwarf sample. The rotation-activity relationship for very low-mass stars through R'(HK). Astronomy & Astrophysics. April 2017, 600: 15. Bibcode:2017A&A...600A..13A. S2CID 119237202. arXiv:1610.09007 . doi:10.1051/0004-6361/201527078. A13.
- ^ 3.0 3.1 West, Andrew A.; et al. An Activity-Rotation Relationship and Kinematic Analysis of Nearby Mid-to-Late-Type M Dwarfs. The Astrophysical Journal. October 2015, 812 (1): 12. Bibcode:2015ApJ...812....3W. S2CID 17434970. arXiv:1509.01590 . doi:10.1088/0004-637X/812/1/3. 3.
- ^ 4.0 4.1 Nidever, David L.; et al. Radial Velocities for 889 Late-Type Stars. The Astrophysical Journal Supplement Series. August 2002, 141 (2): 503–522. Bibcode:2002ApJS..141..503N. S2CID 51814894. arXiv:astro-ph/0112477 . doi:10.1086/340570.
- ^ Anderson, E.; Francis, Ch. XHIP: An extended hipparcos compilation. Astronomy Letters. 2012, 38 (5): 331. Bibcode:2012AstL...38..331A. S2CID 119257644. arXiv:1108.4971 . doi:10.1134/S1063773712050015.
- ^ 6.0 6.1 6.2 Newton, Elisabeth R.; et al. The Hα Emission of Nearby M Dwarfs and its Relation to Stellar Rotation. The Astrophysical Journal. January 2017, 834 (1): 13. Bibcode:2017ApJ...834...85N. S2CID 55000202. arXiv:1611.03509 . doi:10.3847/1538-4357/834/1/85. 85.
- ^ Lépine, Sébastien; et al. A Spectroscopic Catalog of the Brightest (J < 9) M Dwarfs in the Northern Sky. The Astronomical Journal. 2013, 145 (4): 102. Bibcode:2013AJ....145..102L. S2CID 117144290. arXiv:1206.5991 . doi:10.1088/0004-6256/145/4/102.
- ^ 8.0 8.1 Gaidos, Eric; Mann, Andrew W. M dwarf metallicities and giant planet occurrence: ironing out uncertainties and systematics. The Astrophysical Journal. August 2014, 791 (1): 9. Bibcode:2014ApJ...791...54G. S2CID 118744016. arXiv:1406.4071 . doi:10.1088/0004-637X/791/1/54. 54.
- ^ Reiners, Ansgar; et al. The CARMENES search for exoplanets around M dwarfs. High-resolution optical and near-infrared spectroscopy of 324 survey stars. Astronomy and Astrophysics. 2018, 612: A49. Bibcode:2018A&A...612A..49R. S2CID 62818673. arXiv:1711.06576 . doi:10.1051/0004-6361/201732054.
- ^ Meshkat, Tiffany; et al. A Direct Imaging Survey of Spitzer-detected Debris Disks: Occurrence of Giant Planets in Dusty Systems. The Astronomical Journal. December 2017, 154 (6): 21. Bibcode:2017AJ....154..245M. S2CID 42042014. arXiv:1710.04185 . doi:10.3847/1538-3881/aa8e9a. 245.
- ^ YZ CMi. SIMBAD. 斯特拉斯堡天文資料中心.
- ^ Bailer-Jones, C. A. L. Close encounters of the stellar kind. Astronomy & Astrophysics. March 2015, 575: 13. Bibcode:2015A&A...575A..35B. S2CID 59039482. arXiv:1412.3648 . doi:10.1051/0004-6361/201425221. A35.
- ^ Nakajima, Tadashi; Morino, Jun-Ichi. Potential Members of Stellar Kinematic Groups within 30 pc of the Sun. The Astronomical Journal. January 2012, 143 (1): 2. Bibcode:2012AJ....143....2N. doi:10.1088/0004-6256/143/1/2 .
- ^ First flares on a distant star. New Scientist. February 4, 1982: 305.
