Angular Diameters of the Hyades Giants Measured with the CHARA Array

TL;DR

This paper reports precise interferometric measurements of the angular diameters of Hyades giants, enabling improved calibration of stellar parameters such as temperature, radius, and luminosity.

Contribution

It provides highly accurate angular diameters for Hyades giants, leading to a new calibration of stellar effective temperatures with less than 100K error.

Findings

Angular diameters measured with less than 2% error.

Derived stellar parameters including temperature, radius, and luminosity.

Established a new temperature calibration for giant stars.

Abstract

We present angular diameters of the Hyades giants, gamma, delta^1, epsilon, and theta^1 Tau from interferometric measurements with the CHARA Array. Our errors in the limb-darkened angular diameters for these stars are all less than 2%, and in combination with additional observable quantities, we determine the effective temperatures, linear radii and absolute luminosities for each of these stars. Additionally, stellar masses are inferred from model isochrones to determine the surface gravities. These data show that a new calibration of effective temperatures with errors well under 100K is now possible from interferometric angular diameters of stars.