相关论文: Solar twins in M67 : Evolutionary status and lithi…

Following deep astrometric and photometric study of the cluster NGC2682 (M67), we are able to accurately determine its fundamental parameters. Being an old and rich cluster, M67 is a relevant object for the analysis of the Galactic disk…

We have measured an extensive set of UBVRIJHK colors for M31 globular clusters [Barmby et al. 2000]. We compare the predicted simple stellar population colors of three population synthesis models to the intrinsic colors of Galactic and M31…

We present a new catalog of star cluster candidates in the nearby spiral galaxy M33. It is based on eight existing catalogs wherein we have cross-referenced identifications and endeavored to resolve inconsistencies between them. Our catalog…

The analysis of solar-like oscillations for stars belonging to a binary system provides a unique opportunity to probe the internal stellar structure and to test our knowledge of stellar physics. Such oscillations have been recently observed…

Binary systems, in particular eclipsing binaries, are essential sources of our knowledge of the fundamental properties of stars. The ages of binaries, members of open clusters, are constrained by their own fundamental properties and by…

We obtained new multicolour photometry of close binary stars in the young open cluster M35, the solar-age open cluster M67, and the globular cluster M71. New observations have been carried out at the T\"{U}B\.{I}TAK National Observatory…

Solar twins are key in different areas of astrophysics, however only just over a hundred were identified and well-studied in the last two decades. In this work, we take advantage of the very precise \textit{Gaia} (DR2/EDR3), Tycho and 2MASS…

We present spectroscopic ages, metallicities, and [alpha/Fe] ratios for 70 globular clusters in M31 that were derived from Lick line-index measurements. In addition to a population of old (>10 Gyr) globular clusters with a wide range of…

We present Li abundances for 14 solar-type stars in the intermediate age (~ 2 Gyr) clusters IC 4651 and NGC 3680. The log n(Li) vs. effective temperature distributions are compared with those of the similar age cluster NGC 752, of the…

We present new high resolution spectroscopic observations of the intermediate age (~2 Gyr) open cluster NGC 752. We investigate the Li vs. Teff distribution and we obtain a new accurate determination of the cluster metallicity. We compare…

Canonical grids of stellar evolutionary sequences have been computed for the helium mass-fraction abundances $Y = 0.25$, $0.29$, and $0.33$, and for iron abundances that vary from $-2.4$ to $+0.4$ (in 0.2 dex increments) when [$\alpha$/Fe]…

We present precision radial velocities and stellar population parameters for 77 star clusters in the Local Group galaxy M33. Our GTC and WHT observations sample both young, massive clusters and known/candidate globular clusters, spanning…

An extensive grid of metal-rich isochrones utilizing the latest available input physics has been calculated for comparison with the old, metal-rich open cluster NGC 6791. The isochrones have been simultaneously fit to BV and VI color…

Accurate stellar parameters of stars in open clusters can help constrain models of stellar structure and evolution. Here we wish to determine the age and metallicity content of the open cluster NGC 2506. To this end we investigated three…

At an age of 4 Gyr, typical solar-type stars in M67 have rotation rates of 20-30 days. Using K2 Campaign 5 and 16 light curves and the spectral archive of the WIYN Open Cluster Study, we identify eleven three-dimensional kinematic members…

We perform a systematic reanalysis of the age distribution of Galactic open star clusters. Using a catalogue of homogeneously determined ages for 834 open clusters contained in a 2 kpc cylinder around the Sun and characterised with…

Using the most recent proper-motion determination of the old, Solar-metallicity, Galactic open cluster M 67, in orbital computations in a non-axisymmetric model of the Milky Way, including a bar and 3D spiral arms, we explore the…

We present the results of a photometric and spectroscopic survey of cool M dwarf candidates in the young open cluster NGC 2547. Using the 2dF fiber spectrograph, we have searched for the luminosity at which lithium remains unburned in an…

The main goal of this work is to evaluate the correlation between Li abundance, age, and mass. Using high-quality ESO/HARPS data (R $\simeq$ 115 000; 270 $\leq$ SNR $\leq$ 1000), we measured Li abundances via spectral synthesis of the…

We present the first detailed analysis of the detached eclipsing binary V15 in the super-metal rich open cluster NGC 6253. We obtain the following absolute parameters: M_p=1.303+-0.006 Msun, R_p=1.71+-0.03 Rsun, L_p=2.98+-0.10 Lsun for the…