What is the density of the Sun's core?

The density of the Sun’s core is up to 150 g/cm³. This means a cubic centimetre of core material would contain roughly 150 grams of matter—about 150 times the density of liquid water on Earth.

The core occupies the innermost roughly 20–25% of the Sun’s radius. Its enormous pressure and temperature allow hydrogen nuclei to fuse into helium through the proton–proton chain, releasing the energy that ultimately powers sunlight. The core reaches about 15.7 million K, while the visible surface is only about 5,800 K.

The figure is a maximum or representative central density, not the density of every part of the core. Density decreases outward as pressure falls. Nearly all of the Sun’s fusion power is generated in its deepest region; about 99% of its power comes from the innermost 24% of the solar radius.

A common mix-up is confusing core density with the Sun’s average density. Averaged across the entire star, the Sun is only about 1.41 g/cm³ because its outer layers are far less compressed. The extreme central density is a consequence of gravity squeezing the plasma inward.