Stellar Diameters and Temperatures III. Main Sequence A, F, G, & K Stars: Additional high-precision measurements and empirical relations

TL;DR

This paper presents high-precision measurements of stellar diameters and temperatures for 125 main-sequence stars, deriving empirical color-temperature relations across multiple photometric systems to improve stellar characterization.

Contribution

It provides a comprehensive angular diameter anthology and new empirical color-temperature relations for main-sequence stars, including Sun-like stars, based on high-precision interferometric data.

Findings

Derived color-temperature relations with ~3% standard deviation.

Validated temperature estimates against infrared-flux and spectroscopic methods.

Compiled a large, precise dataset of stellar diameters and temperatures.

Abstract

Based on CHARA Array measurements, we present the angular diameters of 23 nearby, main- sequence stars, ranging from spectral type A7 to K0, five of which are exoplanet host stars. We derive linear radii, effective temperatures, and absolute luminosities of the stars using HIPPARCOS parallaxes and measured bolometric fluxes. The new data are combined with previously published values to create an Angular Diameter Anthology of measured angular diameters to main-sequence stars (luminosity class V and IV). This compilation consists of 125 stars with diameter uncertainties of less than 5%, ranging in spectral types from A to M. The large quantity of empirical data are used to derive color-temperature relations to an assortment of color indices in the Johnson (BVRIJHK), Cousins (RI), Kron (RI), Sloan (griz), and WISE (W3W4) photometric systems. These relations have an average standard deviation of ~3% and are valid for stars with spectral types A0 to M4. To derive even more accurate relations for Sun-like stars, we also determined these temperature relations omitting early-type stars (Teff > 6750 K) that may have biased luminosity estimates because of rapid rotation; for this subset the dispersion is only ~2.5%. We find effective temperatures in agreement within a couple percent for the interferometrically characterized sample of main sequence stars compared to those derived via the infrared-flux method and spectroscopic analysis.