Abstract The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is a
dual-hemisphere, near-infrared (NIR), spectroscopic survey with the goal of producing a …

The existing open-cluster membership determination algorithms are either prior dependent
on some known parameters of clusters or are not automatable to large samples of clusters …

Context. In the era of large high-resolution spectroscopic surveys such as Gaia-ESO and
APOGEE, high-quality spectra can contribute to our understanding of the Galactic chemical …

Blue straggler stars (BSSs) are the most massive stars in a cluster formed via binary or
higher order stellar interactions. Though the exact nature of such formation scenarios is …

Context. In Gaia DR2, an unprecedented high level of precision has been reached at sub-
milliarcsecond for astrometry and millimagnitudes for photometry. Using cluster members …

Sub-subgiants are stars that are observed to be redder than normal main-sequence stars
and fainter than normal subgiant (and giant) stars in an optical color–magnitude diagram …

Blue straggler stars (BSS) are well studied in globular clusters but their systematic study with
secure membership determination is lacking in open clusters. We use Gaia DR2 data to …

The open cluster NGC 6791 is among the oldest, most massive, and metal-rich open
clusters in the Galaxy. High-resolution H-band spectra from the Apache Point Observatory …

We present an extensive time-series radial-velocity (RV) survey of stars in the rich open
cluster NGC 7789 (1.6 Gyr,[Fe/H]=+ 0.02). The stellar sample lies within an 18'circular radius …

Sub-subgiant stars (SSGs) lie to the red of the main sequence and fainter than the red giant
branch in cluster color–magnitude diagrams (CMDs), a region not easily populated by …