Time-resolved UVES observations of a stellar flare on the planet host HD 189733 during primary transit
Time-resolved UVES observations of a stellar flare on the planet host HD 189733 during primary transit
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时间分辨 UVES 对主凌日期间 HD 189733 行星上恒星耀斑的观测
DOI：
10.1051/0004-6361/201630068
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Klocova
中科院分区：
文献类型：
--
作者：
Klocova
ContextHD 189733是一个系外行星系统，由一颗凌日的热木星和一颗活动的K2 V型主序星星星组成。在该系统中，我们可以在光学、紫外和X射线波段上重复观测到恒星活动的丰富表现，如光度斑或色球耀斑等。（R= 60000）阶梯光栅光谱研究一次恒星耀斑.方法我们同时分析了几条色球恒星谱线的时间演化，即Ca ii H & K谱线（3933，3968 nm），Hα（6563 nm），Hβ（4861 nm），Hγ（4341 nm），Hδ（4102 nm），H γ（3970 nm），Ca ii红外三线态（8498，8542和8662 nm），He i D3（5875.6 nm）。观测时间分辨率约为1分钟，持续时间为4小时，包括一次完整的行星凌日。结果我们确定所有研究的色球线在耀斑期间释放的能量总和约为8.7 × 1031尔格，这使得该事件处于太阳上观察到的耀斑能量的上端。我们的分析没有显示任何显着的延迟的耀斑峰值中观察到的巴耳末和钙II H & K线，虽然我们发现这些线的时间演化有明显的差异。He i D3显示可能与耀斑事件相关的额外吸收。根据耀斑期间Ca ii H & K谱线释放的通量，估计耀斑期间的软X射线辐射通量为7 × 1030 erg。结论本次耀斑属于K型星星上的中等耀斑，证实HD 189733宿主星星具有较高的活动水平。研究色球线的核心表现出相同的行为，让我们研究耀斑的演变。我们表明，系外行星的主机星星的活动可以发挥重要的作用，在探测系外行星的大气，因为这些经常被发现作为一个额外的吸收线的核心。一个可能的恒星-行星相互作用负责耀斑发生在过境既不能证实也不能排除。
ContextHD 189733 is an exoplanetary system consisting of a transiting hot Jupiter and an active K2V-type main sequence star. Rich manifestations of a stellar activity, like photometric spots or chromospheric flares were repeatedly observed in this system in optical, UV and X-rays.AimsWe aim to use VLT/UVES high resolution (R= 60 000) echelle spectra to study a stellar flare.MethodsWe have performed simultaneous analyses of the temporal evolution in several chromospheric stellar lines, namely, the Ca ii H & K lines (3933, 3968 Å), Hα(6563 Å), Hβ(4861 Å), Hγ(4341 Å), Hδ(4102 Å), Hϵ(3970 Å), the Ca ii infrared triplet lines (8498, 8542 and 8662 Å), and He i D3 (5875.6 Å). Observations were carried out with a time resolution of approximately 1 min for a duration of four hours, including a complete planetary transit.ResultsWe determine the energy released during the flare in all studied chromospheric lines combined to be about 8.7 × 1031erg, which puts this event at the upper end of flare energies observed on the Sun. Our analysis does not reveal any significant delay of the flare peak observed in the Balmer and Ca ii H & K lines, although we find a clear difference in the temporal evolution of these lines. The He i D3 shows additional absorption possibly related to the flare event. Based on the flux released in Ca ii H & K lines during the flare, we estimate the soft X-ray flux emission to be 7 × 1030erg.ConclusionsThe observed flare can be ranked as a moderate flare on a K-type star and confirms a rather high activity level of HD 189733 host star. The cores of the studied chromospheric lines demonstrate the same behavior and let us study the flare evolution. We demonstrate that the activity of an exoplanet host star can play an important role in the detection of exoplanet atmospheres, since these are frequently discovered as an additional absorption in the line cores. A possible star-planet interaction responsible for a flare occurrence during a transit can neither be confirmed nor ruled out.
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影响因子：
6.5
作者：
S. Lalitha;B. Fuhrmeister;U. Wolter;J. Schmitt;D. Engels;M. Wieringa
通讯作者：
S. Lalitha;B. Fuhrmeister;U. Wolter;J. Schmitt;D. Engels;M. Wieringa
光谱中 he i 的激发。
DOI：
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发表时间：
1960
期刊：
影响因子：
--
作者：
R. Athay;H. R. Johnson
通讯作者：
H. R. Johnson
DOI：
10.1046/j.1365-8711.1999.02373.x
发表时间：
1998-11
影响因子：
4.8
作者：
D. Montes;S. Saar;A. Cameron;Y. C. U. D. A. U. C. Madrid-Y.-C.-U.-D.-A.-U.-C.-Madrid-2095782423;P. S. University;Harvard-Smithsonian Cfa;U. St.Andrews;I. Vienna
通讯作者：
D. Montes;S. Saar;A. Cameron;Y. C. U. D. A. U. C. Madrid-Y.-C.-U.-D.-A.-U.-C.-Madrid-2095782423;P. S. University;Harvard-Smithsonian Cfa;U. St.Andrews;I. Vienna
DOI：
10.1086/149652
发表时间：
1968
期刊：
The Astrophysical Journal
影响因子：
--
作者：
O. C. Wilson
通讯作者：
O. C. Wilson
使用 UVES 对 HD 189733b 进行窄带透射光谱分析
DOI：
--
发表时间：
2018
期刊：
影响因子：
--
作者：
S. Khalafinejad;C. V. Essen;H. J. Hoeijmakers;G. Zhou;T. Klocova;J. H. M. M. Schmitt;S. Dreizler;M. López;T. Husser;T. O. B. Schmidt;R. Collet
通讯作者：
R. Collet