P459:5, 41:4.1 The mass of your sun is slightly greater than the estimate of your physicists, who have reckoned it as about two octillion (2 x 10^27) tons. It now exists about halfway between the most dense and the most diffuse stars, having about one and one-half times the density of water. But your sun is neither a liquid nor a solid -- it is gaseous -- and this is true notwithstanding the difficulty of explaining how gaseous matter can attain this and even much greater densities.
P459:6, 41:4.2 Gaseous, liquid, and solid states are matters of atomic-molecular relationships, but density is a relationship of space and mass. Density varies directly with the quantity of mass in space and inversely with the amount of space in mass, the space between the central cores of matter and the particles which whirl around these centers as well as the space within such material particles.
P459:7, 41:4.3 Cooling stars can be physically gaseous and tremendously dense at the same time. You are not familiar with the solar supergases, but these and other unusual forms of matter explain how even nonsolid suns can attain a density equal to iron -- about the same as Urantia -- and yet be in a highly heated gaseous state and continue to function as suns. The atoms in these dense supergases are exceptionally small; they contain few electrons. Such suns have also largely lost their free ultimatonic stores of energy.
P460:1, 41:4.4 One of your near-by suns, which started life with about the same mass as yours, has now contracted almost to the size of Urantia, having become sixty thousand times as dense as your sun. The weight of this hot-cold gaseous-solid is about one ton per cubic inch. And still this sun shines with a faint reddish glow, the senile glimmer of a dying monarch of light.
P460:2, 41:4.5 Most of the suns, however, are not so dense. One of your nearer neighbors has a density exactly equal to that of your atmosphere at sea level. If you were in the interior of this sun, you would be unable to discern anything. And temperature permitting, you could penetrate the majority of the suns which twinkle in the night sky and notice no more matter than you perceive in the air of your earthly living rooms.
P460:3, 41:4.6 The massive sun of Veluntia, one of the largest in Orvonton, has a density only one one-thousandth that of Urantia's atmosphere. Were it in composition similar to your atmosphere and not superheated, it would be such a vacuum that human beings would speedily suffocate if they were in or on it.
P460:4, 41:4.7 Another of the Orvonton giants now has a surface temperature a trifle under three thousand degrees. Its diameter is over three hundred million miles -- ample room to accommodate your sun and the present orbit of the earth. And yet, for all this enormous size, over forty million times that of your sun, its mass is only about thirty times greater. These enormous suns have an extending fringe that reaches almost from one to the other.