Stars are nowhere the size, at the distance they are from Earth, that they appear in your scopes or to your eye when gazing skyward on a clear night. What you see is a diminishing light, from an intense center, to the periphery. Should this circle, the star, have the light uniform, there would be very few stars visible. Why so? The light your eye or scopes are registering is due to the extreme intensity in the very center. In discussions on how many pixels, a point-source, Planet X or a star might assume during viewing, a star always floods more than a pixel with light, as this is dependent more upon the circle that the eye or scope can encompass, not the source. Should this viewing area be reduced to the star itself, and not scattering light, is would be infinitesimally smaller than a pixel. Such is the intensity of light from stars that even at their distance, they flood the viewable area with scattered light that is still intense. Comparing this setup with the diffuse light from a smoldering brown dwarf is akin to comparing the glow from a fire-fly in the nearby bushes to a laser aimed at your eye from a few hundred feet away. If you still had an eye left, you'd know the difference. Intensity matters.