Require a further 4 terms to account for effects in the binary system.
If companion is not compact, require tidal and quadrupole contributions to timing model
Aberration delay due to rotation of the Earth and/or the
Figure 34: Two contributions to the Roemer delay. Left: the radial velocity shifts due to motion in an eccentric binary system. Right: The timing parallax.
Gravitational redshift due to companion
Figure 35: The changing Einstein delay due to precession of the orbit of PSR B1913+16
Figure 36: The Shapiro delay in PSR B1855+09