Stellar radii from long-baseline interferometry

Abstract

Abstract. Long baseline interferometers now measure the angular diameters of nearby stars with sub-percent accuracy. They can be translated in photospheric radii when the parallax is known, thus creating a novel and powerful constraint for stellar models. I present applications of interferometric radius measurements to the modeling of main sequence stars. Over the last few years, we obtained accurate measurements of the linear radius of many of the nearest stars: Procyon A, 61 Cyg A & B, α Cen A & B, Sirius A, Proxima... Firstly, I describe the example of our modeling of Procyon A (F5IV-V) with the CESAM code, constrained using spectrophotometry, the linear radius, and asteroseismic frequencies. I also present our recent results on the low-mass 61 Cyg system (K5V+K7V), for which asteroseismic frequencies have not been detected yet.

High angular resolution imaging with stellar intensity interferometry using air Cherenkov telescope arrays

“…Radii measurements with uncertainties of a few per cent, along with spectroscopic measurements, are necessary to constrain the position of stars in the Hertzsprung–Russell diagram (e.g. Kervella 2008). With the methods described in this paper, we show that diameters can in principle be measured with accuracies better than 1 per cent when using realistic array configurations for future experiments such as Cherenkov Telescope Array (CTA).…”