190 datasets found

The lithium abundances for 378 G/K giants are derived with non-local thermodynamic equilibrium correction considered. Among these are 23 stars that host planetary systems. The...

Atmospheric parameters and oxygen abundances of 825 nearby FGK stars are derived using high-quality spectra and a non-local thermodynamic equilibrium analysis of the 777nm OI...

We derive atmospheric parameters and lithium abundances for 671 stars and include our measurements in a literature compilation of 1381 dwarf and subgiant stars. First, a...

We present the results of a comprehensive search for new companions to nearby solar-type stars using the separated fringe packet (SFP) technique at the Center for High Angular...

We confirm the difference in chemical abundance between stars with and without exoplanets and present the relation between chemical abundances and physical properties of...

We report the discovery of HAT-P-27b, an exoplanet transiting the moderately bright G8 dwarf star GSC 0333-00351 (V=12.214). The orbital period is 3.039586+/-0.000012 days, the...

We test four competing models that aim to explain the nature of stars in spiral galaxies that are well away (>1kpc) from the midplane, the so-called thick disk: the stars may...

We present an analysis of the X-ray properties of a sample of solar- and late-type field stars identified in the Chandra Cosmic Evolution Survey (COSMOS), a deep (160ks) and...

We report the discovery of HAT-P-15b, a transiting extrasolar planet in the "period valley," a relatively sparsely populated period regime of the known extrasolar planets. The...

We present a fully differential chemical abundance analysis using very high resolution ({lambda}/{delta}{lambda}>~85000) and very high signal-to-noise (S/N~800 on average)...

We present a high-resolution spectrum of a microlensed G dwarf in the Galactic bulge with spectroscopic temperature T_eff_=5600+/-180K. This I~21mag star was magnified by a...

We present precision radial velocity data that reveal a multiple exoplanet system orbiting the bright nearby G5V star 61 Virginis. Our 4.6 years of combined Keck/HIRES and...

We have observed 152 nearby solar-type stars with the Infrared Spectrometer (IRS) on the Spitzer Space Telescope. Including stars that met our criteria but were observed in...

While the strong anticorrelation between chromospheric activity and age has led to the common use of the CaII H and K emission index (R'HK=L_HK_/L_bol_) as an empirical age...

We find a significant correlation between the magnetic and rotational moments for a sample of 112 lower main-sequence stars. The rotational moment is calculated from...

We demonstrate an approach to determine spectral energy distribution (SED) templates that are accurate to the 1% level from the visible through the infrared for nearby...

Understanding when and how circumstellar disks disperse is crucial to constrain planet formation and migration. Thermal winds powered by high-energy stellar photons have long...

We report the confirmation of a TESS-discovered transiting super-Earth planet orbiting a mid-G star, HD307842 (TOI-784). The planet has a period of 2.8days, and the radial...

We present the discovery of TOI-1420b, an exceptionally low-density ({rho}=0.08{+/-}0.02g/cm^3^) transiting planet in a P=6.96days orbit around a late G-dwarf star. Using...

To accurately characterize the planets a star may be hosting, stellar parameters must first be well determined. {tau}Ceti is a nearby solar analog and often a target for...