A CATALOG OF ROTATION AND ACTIVITY IN EARLY-M STARS
A CATALOG OF ROTATION AND ACTIVITY IN EARLY-M STARS
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DOI：
10.1088/0004-6256/143/4/93
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发表时间：
2012-01
期刊：
影响因子：
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通讯作者：
A. Reiners;N. Joshi;B. Goldman
中科院分区：
文献类型：
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作者：
A. Reiners;N. Joshi;B. Goldman
我们提出了一个目录的旋转和色球活动的334 M矮星的光谱类型M0-M4.5填充的参数空间周围的边界充分对流的样本。我们获得了206个目标的高分辨率光谱，并确定了投影旋转速度，vsin i和Hα发射。这些数据相结合的测量vsin我在现场的恒星从文献中相同的光谱类型。我们的样本在现有文献中增加了157个新的旋转测量值，几乎使可用的vsin i样本增加了一倍。最后一个样本提供了一个统计上有意义的旋转和活动在过渡到充分的对流在太阳附近的图片。我们证实了急剧上升的活跃的恒星在过渡到充分对流的部分从早期的工作。此外，我们看到同一颗恒星的自转速度明显上升。在极少数恒星中，没有色球活动，但有旋转增宽的检测报告。我们认为，所有这些都可能是虚假的检测;我们得出结论，在我们的样本中，所有显着旋转的恒星都是活跃的，所有活跃的恒星都显着旋转。旋转活动的关系是有效的部分和完全对流星。因此，我们没有观察到任何证据的过渡，从一个旋转为主的发电机在部分对流的恒星旋转独立的湍流发电机在完全对流的恒星;湍流发电机在完全对流的恒星周围的光谱类型M4仍然是由旋转驱动。最后，我们比较了33颗恒星的投影旋转速度的文献中来自测光的旋转周期，并确定其中一些倾斜。
We present a catalog of rotation and chromospheric activity in a sample of 334 M dwarfs of spectral types M0–M4.5 populating the parameter space around the boundary to full convection. We obtain high-resolution optical spectra for 206 targets and determine projected rotational velocity, vsin i, and Hα emission. The data are combined with measurements of vsin i in field stars of the same spectral type from the literature. Our sample adds 157 new rotation measurements to the existing literature and almost doubles the sample of available vsin i. The final sample provides a statistically meaningful picture of rotation and activity at the transition to full convection in the solar neighborhood. We confirm a steep rise in the fraction of active stars at the transition to full convection known from earlier work. In addition, we see a clear rise in rotational velocity in the same stars. In very few stars, no chromospheric activity but a detection of rotational broadening is reported. We argue that all of them are probably spurious detections; we conclude that in our sample all significantly rotating stars are active, and all active stars are significantly rotating. The rotation–activity relation is valid in partially and in fully convective stars. Thus, we do not observe any evidence for a transition from a rotationally dominated dynamo in partially convective stars to a rotation-independent turbulent dynamo in fully convective stars; turbulent dynamos in fully convective stars of spectral types around M4 are still driven by rotation. Finally, we compare projected rotational velocities of 33 stars to rotational periods derived from photometry in the literature and determine inclinations for a few of them.