Telescope Reviews: Why do brighter stars appear "larger" in scopes?

At least in the apertures of even larger amateur telescopes, the angle subtended by the diameter of even relatively close stars such as Vega is far too small to be visibly resolved into a disc rather than (in principle) a point of light no larger than the smallest angular resolution the particular instrument is capable of showing. For example, Vega has an equatorial diameter approximately 2.74x that of the sun, and we can ignore for discussion that its polar diameter is more like 2.25x that of the sun due to distortion induced by rapid rotation. The key thing for our purpose is that since Vega is about 25 light-years distant from earth, we can calculate that it visually subtends an arc approximately 1.61x10^-8 degrees or 4.47x10^-12 arc-seconds from the distance of earth. Even assuming I haven't figured the amount of arc-seconds quite accurately, nevertheless the basic point is correct: the visual angle subtended by its diameter at the distance of earth is too small by an enormous factor to resolve into anything approaching the minimal resolution capability of amateur telescopes.

YET, brighter stars such as Vega unmistakably "appear" quite distinctly larger to us than fainter stars in our telescopes, and even to some extent naked eye. I presume that a key part of the explanation is diffraction effects: in a telescopic view is that the brighter the star, the more light flux is available to spill over into diffraction rings further out from the central axis, and the lenses of our own eyes accomplish the equivalent thing naked-eye. This will be true even of an extremely high-quality optic with a high Strehl ratio, although the amount of light leaking into outer diffraction rings will be less than for a poorer-quality optic. Is this an accurate understanding of why brighter stars appear larger, even to the extent of generating a pseudo-disc in the case of the brightest stars?

I understand that in some very large aperture high-quality professional telescopes, it actually is possible to barely resolve the actual disc of a tiny handful of bright stars at very high magnification, Betelgeuse in particular. However, the essential point remains that this accomplishment is vastly beyond the capabilities of any telescope owned by members of the CN community. Correct, and if so, for the reasons I stated? Or am I merely correct as far as it goes, and there's more to it than just that?