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arXiv 2210.09710astro-ph.SR
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巨星耀斑的特征

Characteristics of flares on giant stars

Katalin Oláh, Bálint Seli, Zsolt Kővári, Levente Kriskovics, Krisztián Vida

摘要:

虽然晚型矮星和巨星有本质上的不同,但它们的耀斑被认为起源于相似的物理过程,只是能级的比例因子不同。我们研究这种方法的有效性。我们寻找耀斑的活动巨星,这可能是统计上不同于主序星的特点。我们使用了近4000个耀斑的61个巨星和20个其他类型的恒星,观察开普勒在长节奏模式,这是唯一合适的数据库进行比较研究。对于每个耀斑,我们推导出持续时间和能量,并收集恒星参数。研究了耀斑特征与各种恒星参数之间的相关性。强烈的相关性之间的耀斑持续时间和表面的重力,光度和恒星的半径。有30分钟节奏的巨星和矮星上的按比例缩放的耀斑形状看起来是相似的。耀斑能量与持续时间的对数关系在表面重力较低的恒星中更为陡峭。观测到的耀斑在巨星上比在矮星上平均更长,能量更高。耀斑能量和持续时间的对数关系的广义线性标度具有普遍的理论斜率$\approx$ 1/3,应通过引入对表面重力的依赖性来稍微修改。

英文摘要:

Although late-type dwarfs and giant stars are substantially different, their flares are thought to originate in similar physical processes and differ only by a scale factor in the energy levels. We study the validity of this approach. We search for characteristics of flares on active giants, which might be statistically different from those on main-sequence stars. We used nearly 4000 flares of 61 giants and 20 stars of other types that were observed with Kepler in long-cadence mode, which is the only suitable database for this comparative study. For every flare, we derived the duration and energy and gathered stellar parameters. Correlations between the flare characteristics and various stellar parameters were investigated. Strong correlations are found between the flare duration and the surface gravity, luminosity, and radii of the stars. Scaled flare shapes appear to be similar on giants and dwarfs with a 30 min cadence. The logarithmic relation of flare energy and duration is steeper for stars with lower surface gravity. Observed flares are longer and more energetic on giants than on dwarfs on average. The generalized linear scaling for the logarithmic relation of flare energy and duration with a universal theoretical slope of $\approx$1/3 should slightly be modified by introducing a dependence on surface gravity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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