Binary-pulsar periastron advance
= Binary-pulsar periastron advance
{title2=$\dot\omega$}
A gradual rotation of the direction of <periapsis> within the <orbital plane>. A closed <Kepler orbit> has fixed <argument of periapsis> $\omega$; relativistic <gravity> can make $\omega$ advance between successive orbits. The angle change and <binary-pulsar orbital decay> describe different changes of the <orbit>.