Eccentricity timeseries

This blog has applied von Zeipel to two systems: GJ 229 and ToI 1408. I have a notion on how to apply this to others.

Say we have a two-body system of a star and a brown-dwarf maybe even red; the latter is visible to our 'scopes. These bodies define the inclination of the overall system. Introduce a[nother] planet around the main star. It is eccentric and inclined. Radial-velocity will catch its eccentricity. The inclination - relative to Earth - is unknown.

Von Zeipel suggests that we could run a time series on the eccentricity and also on the amplitude - apparent msini. As the eccentricity changes, given constant mass so should the amplitude. Constraints on the mass should be visible given better spectrometry.

It gets better: as inclination relative to us hits 90°, which I've admitted won't happen with GJ 229, we will start seeing transits. Yea even unto 1 AU from the host star. On the flipside some of our further-out transits, if they do have large outer planets, stand to shift away from transit over time. Luckily we've now had those snapshots.

Exciting as all this is for mostly-future researchers, I must warn that planets subject to ultraMilankovitch will not be habitable. They'll have ultraIceAges.