Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample

  title={Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample},
  author={R. O. Gray and Christopher J. Corbally and Robert F. Garrison and M. T. McFadden and Eric Bubar and Courtney Elizabeth McGahee and Aileen A. O'Donoghue and E. R. Knox},
We are obtaining spectra, spectral types and basic physical parameters for the nearly 3600 dwarf and giant stars earlier than M0 in the Hipparcos catalog within 40pc of the Sun. Here we report on results for 1676 stars in the southern hemisphere observed at Cerro Tololo Interamerican Observatory and Steward Observatory. These results include new, precise, homogeneous spectral types, basic physical parameters (including the effective temperature, surface gravity, and metallicity, [M/H]) and… Expand
Magnetic fields on young, solar-type stars
This thesis describes an investigation aimed at using spectropolarimetric observations of the magnetic fields of young solar-type stars to improve the understanding of the early development of solarExpand
Chromospheric activity of nearby Sun-like stars
Context.The chromospheric emission in the cores of the Ca IIH & K lines of late-type dwarfs is a well known indicator of magnetic activity that decreases with increasing stellar age.Aims.I use thisExpand
Lyα Observations of High Radial Velocity Low-mass Stars Ross 1044 and Ross 825
The discovery of habitable zone (HZ) planets around low-mass stars has highlighted the need for a comprehensive understanding of the radiation environments in which such planets reside. Of particularExpand
Discovery of new members of the nearby young stellar association in Cepheus
Young field stars are hardly distinguishable from older ones because their space motion rapidly mixes them with the stellar population of the Galactic plane. Nevertheless, a careful target selectionExpand
The average physical properties of A-G stars derived from uvby-H β Strömgren–Crawford photometry as the basis for a spectral-classification synthetical approach
We have revisited and updated the $uvby$ Stromgren colour and colour-index distributions of A, F and early G-type main sequence stars. For this aim, we selected 7054 dwarf stars along with 65 MKExpand
The CARMENES search for exoplanets around M dwarfs
Context. The Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs (CARMENES) survey is searching for Earth-like planets orbiting MExpand
Data-driven stellar parameters for southern TESS FGK targets
We present stellar parameter estimates for 939 457 southern FGK stars that are candidate targets for the Transiting Exoplanet Survey Satellite (TESS) mission. Using a data-driven method similar toExpand
The HARPS search for southern extra-solar planets – XLV. Two Neptune mass planets orbiting HD 13808: a study of stellar activity modelling’s impact on planet detection
We present a comprehensive analysis of 10 years of HARPS radial velocities of the K2V dwarf star HD 13808, which has previously been reported to host two unconfirmed planet candidates. We use theExpand
Precise Dynamical Masses of Directly Imaged Companions from Relative Astrometry, Radial Velocities, and Hipparcos–Gaia DR2 Accelerations
We measure dynamical masses for five objects--three ultracool dwarfs, one low-mass star, and one white dwarf--by fitting orbits to a combination of the Hipparcos-Gaia Catalog of Accelerations,Expand
Activity time series of old stars from late F to early K
Context. Solar simulations and observations show that the detection of long-period Earth-like planets is expected to be very difficult with radial velocity techniques in the solar case because ofExpand