HR 7322 is a bright star that is slightly more evolved than our Sun in the phase of its evolution known as the subgiant phase. This is from an evolutionary point of view a rather quick phase, lasting only a small fraction of its life as a hydrogen-fusion main-sequence star but during which fundamental structural changes occur in the star.
Bright subgiant stars are interesting as they can be studied using different methods. This makes it possible to test predictions from methods that depend more strongly on our current theory of stellar models against less model-dependent methods.
In this study, we compare the stellar radius from interferometry, which is more-or-less a geometric method of deriving the radius and thus depend very little on the stellar models, to stellar radii estimates from the scaling relations and estimates from detailed stellar modelling, which by nature has a high model-dependence.