911 datasets found

Using Hyades photometry published by Mendoza (1967BOTT....4..149M) and other authors, Pinsonneault et al. (2004ApJ...600..946P) have recently concluded that Cousins V-I...

We have obtained spectra for 1273 stars using the 0.9m coude feed telescope at Kitt Peak National Observatory. This telescope feeds the coude spectrograph of the 2.1m telescope....

We present a catalog of J-band (1.08 to 1.35{mu}m) stellar spectra at low resolution (R~400). The targets consist of 105 stars ranging in spectral type from O9.5 to M7 and...

The community agrees that Type Ia Supernovae (SNe Ia) arise from C/O white dwarfs undergoing thermonuclear runaway. However, the full progenitor system and the process that...

We present the first results from our ongoing project to study extremely low-mass (ELM) white dwarfs (WDs) (M<~0.3M{sun}) with the Large Sky Area Multi-Object Fiber...

White dwarf (WD) stars evolve simply and predictably, making them reliable age indicators. However, self-consistent validation of the methods for determining WD total ages has...

We present results from high-resolution (R~40000) spectroscopic observations of over 200 metal-poor stars, mostly selected from the RAVE survey, using the Southern African Large...

Accretion plays an important role in protoplanetary disk evolution, and it is thought that the accretion mechanism changes between low- and high-mass stars. Here we characterize...

The kinematics and dynamics of stellar and substellar populations within young, still-forming clusters provide valuable information for constraining theories of formation...

Magnetic fields and mass accretion processes create dark and bright spots on the surface of young stars. These spots manifest as surface thermal inhomogeneities, which alter the...

Stellar rotation is a fundamental observable that drives different aspects of stellar and planetary evolution. In this work, we present an unprecedented manifold analysis of 160...

Despite the many successes that modern massive star evolutionary theory has enjoyed, reproducing the apparent trend in the relative number of red supergiants (RSGs) and...

We calculate directly determined values for effective temperature (Teff) and radius (R) for 191 giant stars based upon high-resolution angular size measurements from optical...

We present fundamental parameters for 110 canonical K- and M-type (1.3-0.13M_{sun}_) Taurus-Auriga young stellar objects (YSOs). The analysis produces a simultaneous...

Evidence of rotational light modulation in 30%-40% of normal B stars is presented, suggesting the presence of starspots and photospheric activity. On this basis, we propose that...

We present the results of a spectroscopic monitoring program of the Pleiades region aimed at completing the census of spectroscopic binaries in the cluster, extending it to...

The stellar mass-stellar metallicity relation (MZR) is an essential approach to probing the chemical evolution of galaxies. It reflects the balance between galactic feedback and...

We analyze space-based time-series photometry of Sun-like stars, mostly in the Pleiades, but also field stars and the Sun itself. We focus on timescales between roughly 1hr and...

Given their location on the Hertzsprung-Russell (H-R) diagram, thoroughly characterized subgiant stars can place stringent constraints on a wide range of astrophysical problems....

Tidal forces are important for understanding how close binary stars and compact exoplanetary systems form and evolve. However, tides are difficult to model, and significant...