# Is it completely false that the Sun does not revolve round the earth? In what sense? [duplicate]

This is a very naive question but I never fully understood this. For a system of two binary stars moving under the influence of their mutual gravitational forces revolve around their common center of mass. This is the "two-body problem" of undergraduate classical mechanics. However, from the perspective of observer A fixed in star A, star B revolves around it, and from the perspective of observer B fixed in star B, star A revolves around it. None of the observers is preferred. Then in what sense "earth moves around the Sun" is more accurate than the "Sun moves around the earth"?

• We would tend to say both orbit in the gravitational field of the solar system, but this is dominated by the sun. Think of the motion of the centre of mass. Oct 22, 2021 at 5:32
• @JamesK In what sense "the earth revolving around the sun" is more correct than saying the "sun revolving around the earth". Oct 22, 2021 at 5:35
• Yes, I see. I think that is completely answered at the suggested other question. Oct 22, 2021 at 5:36
• If we ignore the other planets, the Sun & Earth travel in elliptical orbits around the Sun-Earth barycentre. But the centre of the Sun is only ~450 km from that barycentre. Oct 22, 2021 at 5:49
• @PM2Ring you should make your comment a proper answer, because imho it is correct and exactly what OP was asking. However, I have seen this question asked a lot here on Astronomy SE. Oct 22, 2021 at 11:44