OB associations are unbound groups of young stars made prominent by their bright OB
members, and have long been thought to be the expanded remnants of dense star clusters …

Extraterrestrial materials, including meteorites, interplanetary dust, and spacecraft-returned
asteroidal and cometary samples, provide a record of the starting materials and early …

This is the first of a series of papers presenting the Modules for Experiments in Stellar
Astrophysics (MESA) Isochrones and Stellar Tracks (MIST) project, a new comprehensive …

BANYAN Σ is a new Bayesian algorithm to identify members of young stellar associations
within 150 pc of the Sun. It includes 27 young associations with ages in the range∼ 1–800 …

The σ Orionis cluster is important for studying protoplanetary disk evolution, as its
intermediate age (∼ 3–5 Myr) is comparable to the median disk lifetime. We use ALMA to …

We present results of a spectroscopic survey for new K-and M-type members of Scorpius–
Centaurus (Sco–Cen), the nearest OB Association (∼ 100–200 pc). Using an X-ray, proper …

Estimates of the mass and age of young stars from their location in the HR diagram are
limited by not only the typical observational uncertainties that apply to field stars, but also by …

When determining absolute ages of identifiably young stellar populations, results strongly
depend on which stars are studied. Cooler (K, M) stars typically yield ages that are …

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 ALMA observations of 106 G-, K-, and M-type stars in the Upper Scorpius OB
Association hosting circumstellar disks. With these data, we measure the 0.88 mm …