Is there empirical evidence that the sun has a very dense core underneath its fiery surface?

Question

Or is it only based on physical principles (which might be wrong in that case)?

Answer 1

Yep. For one thing, we know how massive the Sun is (how much it weighs), and we know that it's more dense in the core because we know the conditions necessary for fusion. Also, the GONG project measures seismic activity on the Sun like we do on the Earth - we can see the vibrations on the surface, and use that to figure out how dense the Sun is at all layers.

Answer 2

There is no empirical evidence,only theory.
Cosmologists have a good handle on what the center of the sun is like but they could be wrong.

Answer 3

A lot is known about the interior of the Sun.

Answer 4

Yes, there is. It's based on the gravitation of the Sun (which is, of course, directly proportional to its mass) and its volume. Knowing mass and volume, it's pretty easy to calculate average density.

HTH ☺

Doug