相关论文: The Distances to Open Clusters as Derived from Mai…

We continue our series of papers on open cluster distances with a critical assessment of the accuracy of main-sequence fitting using isochrones that employ empirical corrections to the color-temperature relations. We use four nearby open…

We extend our effort to calibrate stellar isochrones in the Johnson-Cousins ($BVI_C$) and the 2MASS ($JHK_s$) filter systems based on observations of well-studied open clusters. Using cool main-sequence (MS) stars in Praesepe, we define…

Metallicity is one of four free parameters typically considered when fitting isochrones to the cluster sequence. Unfortunately, this parameter is often ignored or assumed to be solar in most papers. Hence an unknown bias is introduced in…

We perform an extensive test of theoretical stellar models for main-sequence stars in ugriz, using cluster fiducial sequences obtained in the previous paper of this series. We generate a set of isochrones using the Yale Rotating…

Reliable temperature-colour transformations are a necessary ingredient for isochrones to be compared with observed colour-magnitude-diagrams of globular clusters. We show that both theoretical and empirical published transformations to…

Parallax data from the Hipparcos mission allow the direct distance to open clusters to be compared with the distance inferred from main sequence (MS) fitting. There are surprising differences between the two distance measurements, which…

We present a new technique to fit color-magnitude diagrams of open clusters based on the Cross-Entropy global optimization algorithm. The method uses theoretical isochrones available in the literature and maximizes a weighted likelihood…

In the first of a new series of papers on open cluster distances, we use updated stellar evolution models to construct an isochrone appropriate for the Hyades, and compare it with the Hyades eclipsing binary system vB 22. We find that the…

In the context of the luminosity calibration of the nearer stars I discuss the Hipparcos results on distances to nearby OB associations and open clusters. The shortcomings and assumptions in the analyses used to derive these results are…

Age and mass determinations for isolated stellar objects remain model-dependent. While stellar interior and atmospheric theoretical models are rapidly evolving, we need a powerful tool to test them. Open clusters are good candidates for…

Hipparcos parallax measurements of stars in the Pleiades notoriously result in a cluster distance of 118 pc; ~10% shorter than the `classical' results of MS-fitting. In an earlier paper we developed a purely empirical MS-fitting method to…

The Gaia mission has provided highly accurate observations that have significantly reduced the scatter in the colour-magnitude diagrams of open clusters. As a result of the improved isochrone sequence of the open cluster M67, we have…

The discrepancy between the Pleiades cluster distance based on Hipparcos parallaxes and main sequence fitting is investigated on the basis of Stromgren photometry of F-type stars. Field stars with the same metallicity as the Pleiades have…

Recent literature reports a color deviation between observed Gaia color-magnitude diagrams (CMDs) and theoretical model isochrone predictions, particularly in the very low-mass regime. To assess its impact on cluster age determination via…

In a series of three papers, we investigate the current status of published metallicities for open clusters that were derived from a variety of photometric and spectroscopic methods. The current article focuses on spectroscopic methods. The…

The metallicity is a critical parameter that affects the correct determination fundamental characteristics stellar cluster and has important implications in Galactic and Stellar evolution research. Fewer than 10 % of the 2174 currently…

I describe a method to transform a set of stellar evolution tracks onto a uniform basis and then interpolate within that basis to construct stellar isochrones. The method accommodates a broad range of stellar types, from substellar objects…

We present new BVRI photometry for a sample of 54 local G and K stars with accurate Hipparcos parallaxes in the metallicity range -0.4 < [Fe/H] < +0.3. We use this sample to develop a completely model-independent main sequence (MS) fitting…

(Abriged) A new grid of theoretical color indices for the Stromgren uvby photometric system has been derived from MARCS model atmospheres and SSG synthetic spectra for cool dwarf and giant stars. At warmer temperatures this grid has been…

We present new isochrone fits to colour-magnitude diagrams of the Galactic globular cluster NGC\,6205 (M13). We utilise 34 photometric bands from the ultraviolet to mid-infrared by use of data from the {\it HST}, {\it Gaia} DR2, SDSS,…