pint.derived_quantities.dr

pint.derived_quantities.dr(mp: Unit('solMass'), mc: Unit('solMass'), pb: Unit('d'))[source]

Post-Keplerian Roemer delay term

dr (\(\delta_r\)) is part of the relativistic deformation of the orbit

Parameters:
Returns:

dr

Return type:

astropy.units.Quantity

Raises:

Notes

Calculates

\[\delta_r = T_{\odot}^{2/3} \left(\frac{P_b}{2\pi}\right)^{2/3} \frac{3 m_p^2+6 m_p m_c +2m_c^2}{(m_p+m_c)^{4/3}}\]

with \(T_\odot = GM_\odot c^{-3}\).

More details in Timing Models. Also see [12].