摘要：Observations of 48 red-clump stars were obtained in theHband with the PIONIER instrument installed at the Very Large Telescope Interferometer. Limb-darkened angular diameters were measured by fitting radial intensity profileI(r) to square visibility measurements. Half the angular diameters determined have formal errors better than 1.2%, while the overall accuracy is better than 2.7%. Average stellar atmospheric parameters (effective temperatures, metallicities and surface gravities) were determined from new spectroscopic observations and literature data and combined with preciseGaiaparallaxes to derive a set of fundamental stellar properties. These intrinsic parameters were then fitted to existing isochrone models to infer masses and ages of the stars. The added value from interferometry imposes a better and independent constraint on theR −Teffplane. Our derived values are consistent with previous works, although there is a strong scatter in age between various models. This shows that atmospheric parameters, mainly metallicities and surface gravities, still suffer from a non-accurate determination, limiting constraints on input physics and parameters of stellar evolution models.
关键词：entechniques: interferometrictechniques: high angular resolutionstars: late-typestars: fundamental parameters
