Studying the stellar surface structure and magnetic cycles in very active stars using Doppler imaging and long-term photometric observations

除了其他现象外，磁场活跃的恒星由于磁阻对流会在其表面出现凉爽的斑点。在这些恒星中的一些恒星上可以看到的反转现象中，占主导地位的黑子区域在经度上迅速移动了180°。这种行为是一种磁活动的例子，首先在恒星上观察到，然后在太阳上搜索并发现。这种现象背后的机制尚不清楚，它可能代表了一种全新的物理过程，因此对发电机理论和对太阳的理解提出了新的挑战。在理解这一现象方面的进展需要比迄今存在的更详细的观察所作的有重点的努力。我们建议用以下方法详细研究这一现象：a)精选目标的高时间分辨率获得的多普勒图像的时间序列；b)同时进行的高精度测光；c)将新的测光数据与现有的长期测光相结合。这个项目的目的是建立触发器在运行中的详细图像，并将触发器现象与其他恒星参数关联起来，为在发电机理论中解释这一显著现象提供更好的基础。

Magnetically active stars exhibit, among other phenomena, cool spots on their surface due to magnetically blocked convective flows. In the flip-flop phenomenon, which is seen on some of these stars, the dominant spot region shifts rapidly by 180° in longitude. This behaviour is an example of a type of magnetic activity first observed on stars and then searched for and found on the Sun. The mechanism behind this phenomenon is not known and it may represent a totally new physical process, and as such a new challenge to dynamo theory and the understanding of the Sun. Progress in understanding this phenomenon requires the focused effort of much more elaborate observations than what exists to date. We propose to investigate this phenomenon in detail using: a) time-series of Doppler images obtained with high time resolution of well selected targets b) simultaneous high-precision photometry and c) combining the new photometric data with the existing long-term photometric observations. The aim of this project is to build a detailde picture of the flip-flop in action and correlate the flip-flop phenomenon with other stellar parameters, giving a better basis for interpreting this remarkable phenomenon within the dynamo theory.