Sentences with phrase «isochrones with»

Not exact matches

Although our revised temperatures are generally consistent with those reported in the Ecliptic Plane Input Catalog (EPIC), our revised stellar radii are typically 0.13 solar radii (39 %) larger than the EPIC values, which were based on model isochrones that have been shown to underestimate the radii of cool dwarfs.

61 Virginis is a yellow - orange main sequence dwarf of spectral and luminosity type G5 - 6 V, with about 92 to 96 percent of Sol's mass (95 percent using the isochrone mass estimate of Valenti and Fischer, 2005; and NASA Star and Exoplanet Database, based on David F. Gray, 1992), 94 to 98 percent of its diameter (96 percent for Valenti and Fischer, 2005; Johnson and Wright, 1983, page 677; and NASA Star and Exoplanet Database, derived from the exponential formula of Kenneth R. Lang, 1980), and around 78 percent of its visual luminosity and nearly 81 percent of its theoretical bolometric luminosity, with infrared radiation (Sousa et al, 2008; Valenti and Fischer, 2005; NASA Star and Exoplanet Database, based on Kenneth R. Lang, 1980).

With a metallicity around 1.12 Sol's and higher chromospheric activity than Sol the star appears to be 2.5 + / -1.8 billion years old — probably younger than Sol's 4.6 billion years (press release), and one analysis of isochrones suggests that the star may only be 2.0 billion years old (Crepp et al, 2012); and Guinan et al, 1999).

We prepared datasets that allowed us to study the improvement of distance and age estimates with the inclusion of TGAS and Gaia end - of - mission parallax precisions in isochrone fitting.

We use spectroscopic data from a variety of large surveys combined with infra - red photometry from 2MASS and AllWISE and compare these in a Bayesian manner with PARSEC isochrones to derive probability density functions (PDFs) for stellar masses, ages and distances.

We demonstrate that we will be able to improve our distance estimates for about one third of stars in spectroscopic surveys and to decrease log (age) uncertainties by about a factor of two for over 80 % of stars as compared to the uncertainties obtained without parallax priors using Gaia end - of - mission parallaxes consistently with spectrophotometry in isochrone fitting.