Astronomy

A planet hidden in a star's wobble

Separate proper motion, annual parallax and the smaller reflex orbit caused by a planet. Compare the wobble with the chosen measurement noise.

By Mykhailo Makarov

Actual application image

The model and its limits

A circular single-planet orbit around a one-solar-mass star, prescribed sky projection and independent Gaussian position errors. The displayed residual subtracts the known simulated proper motion and parallax; it is not a fitted detection or significance estimate.

Equations used in the module

Equations
p[arcsec] = 1/d[pc]; α[arcsec] = [m_p/(M_*+m_p)] a[AU]/d[pc].

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