蝎虎座EV

**蝎虎座EV**
	; 藝術家對蝎虎座EV上閃焰爆發的概念。
觀測資料; 曆元 J2000
星座	蝎虎座
星官
赤經	22h 46m 49.7323s
赤緯	+44° 20′ 02.368″
視星等（V）	10.09
特性
光谱分类	M3.5
U−B 色指数	+0.83
B−V 色指数	+1.36
变星类型	焰星
天体测定
徑向速度 (Rv)	–1.5 km/s
自行 (μ)	赤经：–704.65 mas/yr ; 赤纬：–459.41 mas/yr
视差 (π)	199.3 ± 0.93 mas
距离	16.37 ± 0.08 ly ; (5.02 ± 0.02 pc)
詳細資料
質量	0.35 M☉
半徑	0.36 R☉
溫度	3,400 ± 18 K
金属量 [Fe/H]	–0.01 ± 0.17 dex
自轉	4.376 days
自轉速度 (v sin i)	4.5 km/s
其他命名
	GJ 873、BD+43 4305、LHS 3853、LTT 16695、HIP 112460、PLX 5520
參考資料庫
SIMBAD	资料

蝎虎座EV（也稱為格利澤873、HIP 112460）是蝎虎座中一颗暗淡的紅矮星，距離太陽大約16.5光年。它是在那個天區中距離太陽最近的恆星，但它的視星等只有10等，勉強可以使用雙筒望遠鏡觀看。蝎虎座EV是一颗光譜類型為M3.5的焰星，會釋放出X射線^[10]。

蝎虎座EV的紫外線波段光度曲線，改編自Abdul-Aziz *et al.'*（1995）^[11]。

在2008年4月25日，美國國家航空暨太空總署的尼爾·格雷爾斯雨燕天文台觀測到來自蝎虎座EV的一次創紀錄閃焰爆發^[12]。這個閃焰的威力比曾經觀測到最強的太陽閃焰還要大數千倍。不過蝎虎座EV離地球比太陽遠很多，因此看起來不如太陽閃焰那麼明亮。如果當時的蝎虎座是出現在夜空中，這次的閃焰爆發就能用肉眼直接看到。這是除了太陽之外，在恆星上所見到最明亮的閃焰事件。

蝎虎座EV是比我們的太陽年輕許多的恆星，估計僅有3億歲，並且仍然在高速自轉。快速自轉，加上內部的對流，產生一個比太陽強很多的磁場。這種強磁場被認為對恆星產生如此明亮的閃焰，有著一定的作用。在閃焰爆發之後，恆星呈現藍色 ^[13]。

參考資料

^ ^1.0 ^1.1 ^1.2 ^1.3 Perryman, M. A. C.; et al. The HIPPARCOS Catalogue. Astronomy & Astrophysics. April 1997, 323: L49–L52. Bibcode:1997A&A...323L..49P.
^ V* EV Lac -- Flare Star. SIMBAD. Centre de Données astronomiques de Strasbourg. [2010-06-12]. （原始内容存档于2017-11-07）.
^ Montes, D.; López-Santiago, J.; Gálvez, M. C.; Fernández-Figueroa, M. J.; De Castro, E.; Cornide, M. Late-type members of young stellar kinematic groups - I. Single stars. Monthly Notices of the Royal Astronomical Society. November 2001, 328 (1): 45–63. Bibcode:2001MNRAS.328...45M. S2CID 55727428. arXiv:astro-ph/0106537  . doi:10.1046/j.1365-8711.2001.04781.x.
^ ^4.0 ^4.1 Erro, B. I. Infrared photometry of UV CET stars. Boletin del Instituto de Tonantzintla. 1971, 6: 143. Bibcode:1971BITon...6..143E.
^ Wilson, Ralph Elmer. General Catalogue of Stellar Radial Velocities. Carnegie Institute Washington D.C. Publication (Washington: Carnegie Institution of Washington). 1953. Bibcode:1953GCRV..C......0W.
^ Gatewood, George; de Jonge, Kiewiet Joost; Stephenson, Bruce. One-milliarsecond precision parallax studies in the regions of Delta Cephei and EV Lacertae. Publications of the Astronomical Society of the Pacific. 1993, 105 (692): 1101–1106. Bibcode:1993PASP..105.1101G. doi:10.1086/133287.
^ ^7.0 ^7.1 ^7.2 Phan-Bao, Ngoc; Martín, Eduardo L.; Donati, Jean-François; Lim, Jeremy. Magnetic Fields in M Dwarfs: Rapid Magnetic Field Variability in EV Lacertae. The Astrophysical Journal. July 2006, 646 (1): L73–L76. Bibcode:2006ApJ...646L..73P. S2CID 18410819. arXiv:astro-ph/0603480  . doi:10.1086/506591.
^ ^8.0 ^8.1 Rojas-Ayala, Bárbara; et al. Metallicity and Temperature Indicators in M Dwarf K-band Spectra: Testing New and Updated Calibrations with Observations of 133 Solar Neighborhood M Dwarfs (PDF). The Astrophysical Journal. April 2012, 748 (2): 93 [2019-09-21]. Bibcode:2012ApJ...748...93R. S2CID 41902340. arXiv:1112.4567  . doi:10.1088/0004-637X/748/2/93. （原始内容存档 (PDF)于2021-01-29）.
^ Testa, Paola; Drake, Jeremy J.; Peres, Giovanni. The Density of Coronal Plasma in Active Stellar Coronae. The Astrophysical Journal. December 2004, 617 (1): 508–530. Bibcode:2004ApJ...617..508T. S2CID 17532089. arXiv:astro-ph/0405019  . doi:10.1086/422355.
^ Schmitt JHMM; Fleming TA; Giampapa MS. The X-ray view of the low-mass stars in the solar neighborhood. Astrophys. J. Sep 1995, 450 (9): 392–400. Bibcode:1995ApJ...450..392S. doi:10.1086/176149.
^ Abdul-Aziz, H.; Abranin, E. P.; Alekseev, I. Yu; Avgoloupis, S.; Bazelyan, L. L.; Beskin, G. M.; Brazhenko, A. I.; Chalenko, N. N.; Cutispoto, G.; Fuensalida, J. J.; Gershberg, R. E.; Kidger, M. R.; Leto, G.; Malkov, Yu. F.; Mavridis, L. N.; Pagano, I.; Panferova, I. P.; Rodono, M.; Seiradakis, J. H.; Sergeev, S. G.; Spencer, R. E.; Shakhovskaya, N. I.; Shakhovskoy, D. N. Coordinated observations of the red dwarf flare star EV Lacertae in 1992. Astronomy and Astrophysics Supplement Series. December 1995, 114: 509–526 [14 January 2022]. （原始内容存档于2022-12-20）.
^ Dunbar, Brian. Smith, Yvette , 编. Pipsqueak Star Unleashes Monster Flare. NASA. May 20, 2008 [2010-06-12]. （原始内容存档于2016-03-15）.
^ https://m.youtube.com/watch?v=rqsckfsXU8U

[aaa323_L49-1] 1.0 ^1.1 ^1.2 ^1.3 Perryman, M. A. C.; et al. The HIPPARCOS Catalogue. Astronomy & Astrophysics. April 1997, 323: L49–L52. Bibcode:1997A&A...323L..49P.

[simbad-2] V* EV Lac -- Flare Star. SIMBAD. Centre de Données astronomiques de Strasbourg. [2010-06-12]. （原始内容存档于2017-11-07）.

[mnras3218_1_45-3] Montes, D.; López-Santiago, J.; Gálvez, M. C.; Fernández-Figueroa, M. J.; De Castro, E.; Cornide, M. Late-type members of young stellar kinematic groups - I. Single stars. Monthly Notices of the Royal Astronomical Society. November 2001, 328 (1): 45–63. Bibcode:2001MNRAS.328...45M. S2CID 55727428. arXiv:astro-ph/0106537  . doi:10.1046/j.1365-8711.2001.04781.x.

[bit6_143-4] 4.0 ^4.1 Erro, B. I. Infrared photometry of UV CET stars. Boletin del Instituto de Tonantzintla. 1971, 6: 143. Bibcode:1971BITon...6..143E.

[gcsrv-5] Wilson, Ralph Elmer. General Catalogue of Stellar Radial Velocities. Carnegie Institute Washington D.C. Publication (Washington: Carnegie Institution of Washington). 1953. Bibcode:1953GCRV..C......0W.

[Gatewood1993-6] Gatewood, George; de Jonge, Kiewiet Joost; Stephenson, Bruce. One-milliarsecond precision parallax studies in the regions of Delta Cephei and EV Lacertae. Publications of the Astronomical Society of the Pacific. 1993, 105 (692): 1101–1106. Bibcode:1993PASP..105.1101G. doi:10.1086/133287.

[apj646_1_L73-7] 7.0 ^7.1 ^7.2 Phan-Bao, Ngoc; Martín, Eduardo L.; Donati, Jean-François; Lim, Jeremy. Magnetic Fields in M Dwarfs: Rapid Magnetic Field Variability in EV Lacertae. The Astrophysical Journal. July 2006, 646 (1): L73–L76. Bibcode:2006ApJ...646L..73P. S2CID 18410819. arXiv:astro-ph/0603480  . doi:10.1086/506591.

[apj748_2_934-8] 8.0 ^8.1 Rojas-Ayala, Bárbara; et al. Metallicity and Temperature Indicators in M Dwarf K-band Spectra: Testing New and Updated Calibrations with Observations of 133 Solar Neighborhood M Dwarfs (PDF). The Astrophysical Journal. April 2012, 748 (2): 93 [2019-09-21]. Bibcode:2012ApJ...748...93R. S2CID 41902340. arXiv:1112.4567  . doi:10.1088/0004-637X/748/2/93. （原始内容存档 (PDF)于2021-01-29）.

[apj617_1_508-9] Testa, Paola; Drake, Jeremy J.; Peres, Giovanni. The Density of Coronal Plasma in Active Stellar Coronae. The Astrophysical Journal. December 2004, 617 (1): 508–530. Bibcode:2004ApJ...617..508T. S2CID 17532089. arXiv:astro-ph/0405019  . doi:10.1086/422355.

[Schmitt-10] Schmitt JHMM; Fleming TA; Giampapa MS. The X-ray view of the low-mass stars in the solar neighborhood. Astrophys. J. Sep 1995, 450 (9): 392–400. Bibcode:1995ApJ...450..392S. doi:10.1086/176149.

[Abdul1995-11] Abdul-Aziz, H.; Abranin, E. P.; Alekseev, I. Yu; Avgoloupis, S.; Bazelyan, L. L.; Beskin, G. M.; Brazhenko, A. I.; Chalenko, N. N.; Cutispoto, G.; Fuensalida, J. J.; Gershberg, R. E.; Kidger, M. R.; Leto, G.; Malkov, Yu. F.; Mavridis, L. N.; Pagano, I.; Panferova, I. P.; Rodono, M.; Seiradakis, J. H.; Sergeev, S. G.; Spencer, R. E.; Shakhovskaya, N. I.; Shakhovskoy, D. N. Coordinated observations of the red dwarf flare star EV Lacertae in 1992. Astronomy and Astrophysics Supplement Series. December 1995, 114: 509–526 [14 January 2022]. （原始内容存档于2022-12-20）.

[nasa1087-12] Dunbar, Brian. Smith, Yvette , 编. Pipsqueak Star Unleashes Monster Flare. NASA. May 20, 2008 [2010-06-12]. （原始内容存档于2016-03-15）.

[13] ttps://m.youtube.com/watch?v=rqsckfsXU8U

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觀測資料曆元 J2000
藝術家對蝎虎座EV上閃焰爆發的概念。
星座	蝎虎座
星官
赤經	22^h 46^m 49.7323^s^[1]
赤緯	+44° 20′ 02.368″^[1]
視星等（V）	10.09^[2]
特性
光谱分类	M3.5^[3]
U−B 色指数	+0.83^[4]
B−V 色指数	+1.36^[4]
变星类型	焰星
天体测定

徑向速度 (R_v)	–1.5^[5] km/s
自行 (μ)	赤经：–704.65^[1] mas/yr 赤纬：–459.41^[1] mas/yr
视差 (π)	199.3 ± 0.93^[6] mas
距离	16.37 ± 0.08 ly (5.02 ± 0.02 pc)

詳細資料

質量	0.35^[7] M_☉
半徑	0.36^[7] R_☉
溫度	3,400 ± 18^[8] K
金属量 [Fe/H]	–0.01 ± 0.17^[8] dex
自轉	4.376 days^[9]
自轉速度 (v sin i)	4.5^[7] km/s

其他命名
GJ 873、BD+43 4305、LHS 3853、LTT 16695、HIP 112460、PLX 5520
參考資料庫
SIMBAD	资料