ﻻ يوجد ملخص باللغة العربية
Using a sample of 68 planet-hosting stars I carry out a comparison of isochrone fitting and gyrochronology to investigate whether tidal interactions between the stars and their planets are leading to underestimated ages using the latter method. I find a slight tendency for isochrones to produce older age estimates but find no correlation with tidal time-scale, although for some individual systems the effect of tides might be leading to more rapid rotation than expected from the stars isochronal age, and therefore an underestimated gyrochronology age. By comparing to planetary systems in stellar clusters, I also find that in some cases isochrone fitting can overestimate the age of the star. The evidence for any bias on a sample-wide level is inconclusive. I also consider the subset of my sample for which the sky-projected alignment angle between the stellar rotation axis and the planets orbital axis has been measured, finding similar patterns to those identified in the full sample. However, small sample sizes for both the misaligned and aligned systems prevent strong conclusions from being drawn.
We present a new age-dating technique that combines gyrochronology with isochrone fitting to infer ages for FGKM main-sequence and subgiant field stars. Gyrochronology and isochrone fitting are each capable of providing relatively precise ages for fi
Precise and, if possible, accurate characterization of exoplanets cannot be dissociated from the characterization of their host stars. In this chapter we discuss different methods and techniques used to derive fundamental properties and atmospheric p
The chemical composition of exoplanet host stars is an important factor in understanding the formation and characteristics of their orbiting planets. The best example of this to date is the planet-metallicity correlation. Other proposed correlations
We use near-infrared interferometric data coupled with trigonometric parallax values and spectral energy distribution fitting to directly determine stellar radii, effective temperatures, and luminosities for the exoplanet host stars 61 Vir, $rho$ CrB
The mean density of a star transited by a planet, brown dwarf or low mass star can be accurately measured from its light curve. This measurement can be combined with other observations to estimate its mass and age by comparison with stellar models. O