I know ordinarily a star's mass and radius tend to be proportional, so a 0.5 solar masses star tends to be about 0.5 solar radii and have a density of 4.82 g/cm³, 3.42 or about three and a half times the Sun's.
But, is it theoretically possible to have a main sequence star with 0.77 solar masses while still only being 0.54 solar radii? This comes out to a density of 6.88 g/cm³, 4.88 or about five times the Sun's.
This represents a density 1.43 or about one and a half times denser than "usual".
Can this happen in nature?