相关论文: Lithium abundance/surface activity connections in …

Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a…

This study investigates the temporal and spatial variations in lithium abundance within the Milky Way using a sample of 22,034 main-sequence turn-off (MSTO) stars and subgiants, characterised by precise stellar ages, 3D NLTE (non-local…

We present first results from a multi-object spectroscopy campaign in IC2602, the Hyades, the Pleiades, and the Coma cluster using VLT/FLAMES. We analysed the data for radial velocity, rotational velocity, and H-alpha activity. Here, we…

We report discovery of significant depletion of Li on the surfaces of F dwarf stars in the 150-Myr-old open cluster M35, analagous to a feature in the 700-Myr-old Hyades cluster that has been referred to as the ``Li gap.'' We have caught…

We monitored the chromospheric activity in the Ca II H & K lines of 13 solar-type stars (including the Sun); 8 of them over three years at the CFHT and 5 in a single run at the VLT. Ten of the 13 targets have close planetary companions. All…

$\require{mediawiki-texvc}$A stellar chromospheric activity database of solar-like stars is constructed based on the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Low-Resolution Spectroscopic Survey (LRS). The database…

Using precise measurements of the helium D3 line, we have searched for statistically significant variations in the strength of chromospheric activity in 13 early F-type stars and two late F-type stars. In two early F-type stars, we find…

We perform mode identification for five $\delta$ Scuti stars in the Pleiades star cluster, using custom light curves from K2 photometry. By creating \'echelle diagrams, we identify radial and dipole mode ridges, comprising a total of 28…

We present the non-local thermodynamic equilibrium (non-LTE) calculations for O I with the updated model atom that includes quantum-mechanical rate coefficients for O I + H I inelastic collisions from the recent study of Barklem (2018). The…

With an aim to study whether the close correlation between [Na/H] and [Fe/H] recently found in A-type stars further persists in the regime of B-type stars, the abundances of Na were determined for 30 selected sharp-lined late B-type stars…

Low-mass (< 1.2 Solar mass) main-sequence stars lose angular momentum over time, leading to a decrease in their magnetic activity. The details of this rotation-activity relation remain poorly understood. Using observations of members of the…

Our aim is investigating surface inhomogeneities of the young late-type star SAO51891, from photosphere to upper chromosphere, analyzing contemporaneous high-resolution spectra and broad-band photometry. The FOCES@CAHA spectral range is…

We present Spitzer MIPS observations at 24 um of 37 solar-type stars in the Pleiades and combine them with previous observations to obtain a sample of 71 stars. We report that 23 stars, or 32 +/- 6.8%, have excesses at 24 um at least 10%…

Observations of interstellar lithium provide a valuable complement to studies of lithium in Pop I and Pop II stars. Large corrections for unseen LiII and for non-gas phase lithium have provided obstacles to using interstellar data for…

Branching fraction measurements from Fourier transform spectra in conjunction with published radiative lifetimes are used to determine transition probabilities for 263 lines of neutral chromium. These laboratory values are employed to…

Lithium and beryllium are destroyed at different temperatures in stellar interiors. As such, their relative abundances offer excellent probes of the nature and extent of mixing processes within and below the convection zone. We determine Be…

Using a sample of 116 wide binary systems as coeval and chemically homogeneous stellar pairs, we investigate the factors governing lithium depletion in main-sequence stars. We recover the well-established morphology of the…

The rapidly rotating cool dwarfs of the Pleiades are rich in lithium relative to their slowly rotating counterparts. Motivated by observations of inflated radii in young, active stars, and by calculations showing that radius inflation…

Lithium is a fragile but crucial chemical element in the universe, exhibits interesting and complex behaviors. Thanks to the massive spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)…

The pre-Galactic abundance of lithium offers a unique window into non-thermal cosmological processes. The primordial Li abundance is guaranteed to be present and probes big bang nucleosynthesis (BBN), while an additional Li component is…