Related papers: A search for Maunder-minimum candidate stars

We present results from a medium-resolution (R ~ 2, 000) spectroscopic follow-up campaign of 1,694 bright (V < 13.5), very metal-poor star candidates from the RAdial Velocity Experiment (RAVE). Initial selection of the low-metallicity…

Very metal-poor stars are of obvious importance for many problems in chemical evolution, star formation, and galaxy evolution. Finding complete samples of such stars which are also bright enough to allow high-precision individual analyses…

We present a novel analysis of the metal-poor star sample in the complete Radial Velocity Experiment (RAVE) Data Release 5 catalog with the goal of identifying and characterizing all very metal-poor stars observed by the survey. Using a…

With the dual aims of enlarging the list of extremely metal-poor stars identified in the Galaxy, and boosting the numbers of moderately metal-deficient stars in directions that sample the rotational properties of the thick disk, we have…

For a sample of metal-poor stars (-3.3< [Fe/H] <-2.2) that have high-resolution spectroscopic abundance determinations, we have measured equivalent widths (EW) of the Ca II K, Mg I b and near-infrared (NIR) Ca II triplet lines using…

RAVE, the unbiased magnitude limited survey of the southern sky stars, contained 456,676 medium-resolution spectra at the time of our analysis. Spectra cover the CaII IRT range which is a known indicator of chromospheric activity. Our…

The solar analogs of M67 let us glimpse the probable behavior of the Sun on time scales surpassing the duration of human civilization. M67 can serve as a solar proxy because its stars share a similar age and composition with the Sun.…

The SkyMapper Southern Sky Survey is carrying out a search for the most metal-poor stars in the Galaxy. It identifies candidates by way of its unique filter set that allows for estimation of stellar atmospheric parameters. The set includes…

This paper presents the detailed abundances and r-process classifications of 126 newly identified metal-poor stars as part of an ongoing collaboration, the R-Process Alliance. The stars were identified as metal-poor candidates from the…

We present the results from high-resolution spectroscopic measurements to determine metallicities and activities of bright stars in the southern hemisphere. We have measured the iron abundances ([Fe/H]) and chromospheric emission indices…

The MEarth Project is a photometric survey systematically searching the smallest stars nearest to the Sun for transiting rocky planets. Since 2008, MEarth has taken approximately two million images of 1844 stars suspected to be mid-to-late…

We present and discuss the results of a search for extremely metal-poor stars based on photometry from data release DR1.1 of the SkyMapper imaging survey of the southern sky. In particular, we outline our photometric selection procedures…

The chemical abundances for five metal-poor stars in and towards the Galactic bulge have been determined from H-band infrared spectroscopy taken with the RAVEN multi-object adaptive optics science demonstrator and the IRCS spectrograph at…

The Ca~II H \& K lines are among the few features available to infer the metallicity of extremely metal-poor stars from medium-resolution spectroscopy. Unfortunately, these lines can overlap with absorption produced in the intervening…

The Edinburgh-Cape Blue Object Survey is an ongoing project to identify and analyse a large sample of hot stars selected initially on the basis of photographic colours (down to a magnitude limit B~18.0) over the entire…

Metal-poor solar-type stars display a significant reduction in metal-line blanketing at short wavelengths, leading to an excess of near-ultraviolet (NUV) flux compared to their metal-rich counterparts. We utilize GALEX NUV and $\it{Gaia}$…

Context. The study of the oldest and most metal-poor stars in our Galaxy promotes our understanding of the Galactic chemical evolution and the beginning of Galaxy and star formation. However, they are notoriously difficult to find, with…

We have identified 317 stars included in the Hipparcos astrometric catalogue which have parallaxes measured to a precision of better than 15%, and whose location in the (M_V, (B-V)_T) diagram implies a metallicity comparable to or less than…

We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars…

We present equivalent widths, improved model atmosphere parameters, and revised abundances for 14 species of 11 elements derived from high resolution optical spectroscopy of 311 metal-poor stars. All of these stars had their parameters…