Transit timing variations

Today is a work day... sort of. I'm ducking out to follow up on a use for better spectrometry. And'also to assure my readers I'm not dead.

On Youtube one of the sciencey channels discussed how to sort out the noise in a transit. Sometimes, there's a pattern in the timing of the transits. This may be secular-drift from another body. That other body could be its moon. But usually a transit is seen in the first place because the planet is close to its star... too close for a moon. Alternat(iv)ely the other body may be an outer planet, not detected because it runs oblique relative to that planet and our 'scopes out here.

So here are a few papers to discuss some mathematic models: TrES-2b, from the TESS telescope; and this month Simultaneous Impact Parameter Variation Analysis mainly from the Kepler scope. Lately Daniel Yahalomi and David Kipping's publons on the exoplanet-edge and on the landscape.