Whether the stellar initial mass function (IMF) is universal or is instead sensitive to
environmental conditions is of critical importance: The IMF influences most observable …

The age of an individual star cannot be measured, only estimated through mostly model-
dependent or empirical methods, and no single method works well for a broad range of …

While the strong anticorrelation between chromospheric activity and age has led to the
common use of the Ca ii H and K emission index (R^{\prime} _ {\mathrm {HK}\,}= L …

We present and discuss new determinations of metallicity, rotation, age, kinematics, and
Galactic orbits for a complete, magnitude-limited, and kinematically unbiased sample of 16 …

We here develop an improved way of using a rotating star as a clock, set it using the Sun,
and demonstrate that it keeps time well. This technique, called gyrochronology, derives ages …

We propose a simple interpretation of the rotation period data for solar-and late-type stars.
The open cluster and Mount Wilson star observations suggest that rotating stars lie primarily …

We present a spectroscopic analysis of over 38,000 low-mass stars from the Sloan Digital
Sky Survey (SDSS) Data Release 5 (DR5). Analysis of this unprecedentedly large sample …

The prospects for the habitability of M-dwarf planets have long been debated, due to key
differences between the unique stellar and planetary environments around these low-mass …

Recent observations have shown that globular clusters contain a significant binary
population. This is a dramatic change from the conventional view of even a decade ago …

More than 800 southern stars within 50 pc have been observed for chromospheric emission
in the cores of the Ca II H and K lines. Most of the sample targets were chosen to be G …