A Catalog of Calibrator Stars for Next-Generation Optical Interferometers

TL;DR

This paper presents a comprehensive catalog of 1523 bright northern hemisphere stars with accurately derived angular diameters, serving as calibrators for optical interferometry, validated against existing measurements and providing an online resource.

Contribution

It provides a uniformly computed, vetted catalog of calibrator stars with spectral energy distribution fitting and validation, enhancing interferometric calibration accuracy.

Findings

High agreement between derived and interferometric diameters.

Catalog includes quality metrics and an online SED fit atlas.

Enables better selection of calibrator stars for optical interferometry.

Abstract

Benchmark stars with known angular diameters are key to calibrating interferometric observations. With the advent of optical interferometry, there is a need for suitably bright, well-vetted calibrator stars over a large portion of the sky. We present a catalog of uniformly computed angular diameters for 1523 stars in the northern hemisphere brighter than V = 6 and with declinations $-15^\circ < \delta < 82^\circ$. The median angular stellar diameter is 0.527 mas. The list has been carefully cleansed of all known binary and multiple stellar systems. We derive the angular diameters for each of the stars by fitting spectral templates to the observed spectral energy distributions (SEDs) from literature fluxes. We compare these derived angular diameters against those measured by optical interferometry for 75 of the stars, as well as to 176 diameter estimates from previous calibrator catalogs, finding in general excellent agreement. The final catalog includes our goodness-of-fit metrics as well as an online atlas of our SED fits. The catalog presented here permits selection of the best calibrator stars for current and future visible-light interferometric observations.