獅子座AD

AD Leonis

獅子座AD上耀斑的U、B、V 和 R光變曲線[1]
觀測資料 曆元 J2000
星座	獅子座
星官
赤經	10^h 19^m 36.277^s[2]
赤緯	+19° 52′ 12.06″[2]
視星等（V）	9.32[3]
特性
光谱分类	M3.5eV[4]
U−B 色指数	+1.06[3]
B−V 色指数	+1.54[3]
变星类型	耀星[5]
天体测定
徑向速度 (Rv)	+10.8[6] km/s
自行 (μ)	赤经：–501.8[2] mas/yr 赤纬：–42.8[2] mas/yr
视差 (π)	201.4064 ± 0.0296[7] mas
距离	16.194 ± 0.002 ly (4.9651 ± 0.0007 pc)
绝对星等 (MV)	10.87[8]
詳細資料
質量	0.39–0.42[8][9] M☉
半徑	0.39[9] R☉
表面重力 (log g)	4.79[10]
亮度	0.024[10] L☉
溫度	3,390 ± 19[11] K
金属量 [Fe/H]	+0.28 ± 0.17[11] dex
自轉速度 (v sin i)	3[9][12] km/s
年齡	25-300[13] Myr
其他命名
Gliese 388, BD+20 2465, G 54-23, LHS 5167, LTT 12761, NLTT 24015, SAO 81292, PLX 2420, TYC 1423-174-1[14]
參考資料庫
SIMBAD	资料
AD Leonis 獅子座AD在獅子座的位置

獅子座AD(Gliese 388)是一顆位於獅子座紅矮星。距離太陽大約有16光年。獅子座AD是一顆光譜分類為M3.5V的主序星。 ^[4]它是一顆亮度隨機增加的耀星。^[5][14]

特性

獅子座AD是一顆M型星，光譜類型為M3.5eV，表明它是一顆主序星。它的視星等為9.43。^[8][10] 它大約有太陽質量的39–42%——高於恆星完全對流的質量^[15] — 和太陽半徑的39%。^[8][9]這顆恆星的預計自轉速度僅為3 公里/秒，^[12]但它每 2.24 天完成一次自轉。^[15]它是一顆相對年輕的恆星，估計年齡為25億年，^[13]並被認為是年輕盤星族的一員。^[16]

1943年麦考密克天文台的自行研究中，它被懷疑有伴星。然而，1968 年的一項研究未能證實這一結果。^[17] 1997年使用近紅外散斑干涉儀進行的搜索未能檢測到一顆距離恆星1-10個天文單位的伴星。^[18]2001年，光學日冕儀被用來對這顆恆星進行示例，但沒有發現伴星。^[19]它的徑向速度沒有變化的跡象，表明存在看不見的伴星。^[10]

這顆恆星以0.028的離心率繞銀河系運行。這使得恆星距離銀心近8.442kpc，遠至8.926kpc。軌道傾角將它帶到距銀河系平面0.121 kpc遠的地方。^[20]

2021年，XMM-Newton在 X 射線和TESS在光學上同時觀測到獅子座AD上的超級耀斑。^[21]

參見

• 鄰近恆星列表

參考資料

1. Hawley, Suzanne L.; Pettersen, Bjorn R. The Great Flare of 1985 April 12 on AD Leonis. The Astrophysical Journal. September 1991, 378: 725 [17 January 2022]. Bibcode:1991ApJ...378..725H. doi:10.1086/170474. （原始内容存档于2023-03-20）. 
2. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; et al. The Tycho-2 catalogue of the 2.5 million brightest stars. Astronomy and Astrophysics. March 2000, 355: L27–L30. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862. 
3. Nicolet, B. Catalogue of homogeneous data in the UBV photoelectric photometric system. Astronomy and Astrophysics Supplement Series. October 1978, 34: 1–49. Bibcode:1978A&AS...34....1N. 
4. Shkolnik, Evgenya; Liu, Michael C.; Reid, I. Neill. Identifying the young low-mass stars within 25 pc. I. Spectroscopic observations. The Astrophysical Journal. July 2009, 699 (1): 649–666. Bibcode:2009ApJ...699..649S. S2CID 118623086. arXiv:0904.3323 . doi:10.1088/0004-637X/699/1/649. 
5. Kukarkin, B. V.; Kholopov, P. N.; Pskovsky, Y. P.; Efremov, Y. N.; Kukarkina, N. P.; Kurochkin, N. E.; Medvedeva, G. I. The third edition, containing information on 20,437 variable stars discovered and designated till 1968. General Catalogue of Variable Stars 3rd. 1971. Bibcode:1971GCVS3.C......0K. 
6. Evans, D. S. The revision of the General Catalogue of Radial Velocities. Batten, Alan Henry; Heard, John Frederick (编). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. 20–24 June 1966. Bibcode:1967IAUS...30...57E. 
7. 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.
8. The One Hundred Nearest Star Systems. Georgia State University. 1 January 2009 [2009-09-25]. （原始内容存档于2007-11-12）.  已忽略未知参数|collaboration= (帮助)
9. Reiners, Ansgar; Basri, Gibor; Browning, Matthew. Evidence for magnetic flux saturation in rapidly rotating M stars (PDF). The Astrophysical Journal. February 2009, 692 (1): 538–545 [2021-09-11]. Bibcode:2009ApJ...692..538R. S2CID 15833388. arXiv:0810.5139 . doi:10.1088/0004-637X/692/1/538. hdl:10871/10302. （原始内容存档 (PDF)于2021-09-11）. 
10. Pettersen, B. R.; Coleman, L. A. Chromospheric lines in red dwarf flare stars, I - AD Leonis and GX Andromedae. Astrophysical Journal. December 1981, 251 (12): 571–82. Bibcode:1981ApJ...251..571P. doi:10.1086/159500. 
11. Rojas-Ayala, Bárbara; Covey, Kevin R.; Muirhead, Philip S.; Lloyd, James P. Metallicity and temperature indicators in M dwarf K band spectra: Testing new and updated calibrations with observations of 133 Solar neighborhood M dwarfs. The Astrophysical Journal. April 2012, 748 (2): 93. Bibcode:2012ApJ...748...93R. S2CID 41902340. arXiv:1112.4567 . doi:10.1088/0004-637X/748/2/93. 
12. Reiners, Ansgar. The narrowest M dwarf line profiles and the rotation-activity connection at very slow rotation. Astronomy and Astrophysics. May 2007, 467 (1): 259–268. Bibcode:2007A&A...467..259R. S2CID 8672566. arXiv:astro-ph/0702634 . doi:10.1051/0004-6361:20066991. 
13. Shkolnik, Evgenya; Liu, Michael C.; Reid, I. Neill. Identifying the young low-mass stars within 25 pc. I. Spectroscopic observations. The Astrophysical Journal. July 2009, 699 (1): 649–666. Bibcode:2009ApJ...699..649S. S2CID 118623086. arXiv:0904.3323 . doi:10.1088/0004-637X/699/1/649. 
14. V* AD Leo – Flare Star. SIMBAD. Centre de Données astronomiques de Strasbourg. [2009-09-25]. （原始内容存档于2023-03-21）. 
15. Reiners, Ansgar; Basri, Gibor. On the magnetic topology of partially and fully convective stars. Astronomy and Astrophysics. March 2009, 496 (3): 787–790. Bibcode:2009A&A...496..787R. S2CID 15159121. arXiv:0901.1659 . doi:10.1051/0004-6361:200811450. 
16. Sciortino, S.; Maggio, A.; Favata, F.; Orlando, S. X-ray spectroscopy of the active dM stars: AD Leo and EV Lac. Astronomy & Astrophysics. February 1999, 342 (2): 502–14. Bibcode:1999A&A...342..502S. 
17. Lippincott, S. L. Astrometric study of BD+20 2465 from photographs taken with the Sproul 24 inch refractor. Astronomical Journal. March 1969, 74: 224–228. Bibcode:1969AJ.....74..224L. doi:10.1086/110795. 
18. Oppenheimer, B. R.; Golimowski, D. A.; Kulkarni, S. R.; Matthews, K.; Nakajima, T.; Creech-Eakman, M.; Durrance, S.T. A coronagraphic survey for companions of stars within 8 parsecs. The Astronomical Journal. April 2001, 121 (4): 2189–2211. Bibcode:2001AJ....121.2189O. S2CID 119092593. arXiv:astro-ph/0101320 . doi:10.1086/319941. 
19. Leinert, C.; Henry, T.; Glindemann, A.; McCarthy, D. W., Jr. A search for companions to nearby southern M dwarfs with near-infrared speckle interferometry. Astronomy and Astrophysics. September 1997, 325: 159–166. Bibcode:1997A&A...325..159L. 
20. Allen, C.; Herrera, M. A. The galactic orbits of nearby UV Ceti stars. Revista Mexicana de Astronomía y Astrofísica. April 1998, 34: 37–46. Bibcode:1998RMxAA..34...37A. 
21. Stelzer, B.; Caramazza, M.; Raetz, St.; Argiroffi, C.; Coffaro, M. The Great Flare of 2021 November 19 on AD Leo. Simultaneous XMM-Newton and TESS observations. Solar and Stellar Astrophysics. 2022. S2CID 252199896. arXiv:2209.05068 . doi:10.1051/0004-6361/202244642. 

外部連結

• Segura, Antígona; Walkowicz, Lucianne M.; Meadows, Victoria; Kasting, James; Hawley, Suzanne. The effect of a strong stellar flare on the atmospheric chemistry of an Earth-like planet orbiting an M dwarf. Astrobiology. 2010, 10 (7): 751–771. Bibcode:2010AsBio..10..751S. PMC 3103837 . PMID 20879863. arXiv:1006.0022 . doi:10.1089/ast.2009.0376.