I used data from K2 to confirm the existence of TRAPPIST-1h, determine its orbital period,
measure the rotation period of the star, and establish that all seven planets in
are in the most complex known chain of three-body Laplace resonances.
Check out the links above for the code and the paper.
Long cadence light curve of TRAPPIST-1 observed by K2,
before (top) and after (bottom)
de-trending with my everest
software. The photometric precision afforded by
everest made it possible to
detect planet h, the smallest and farthest out planet in
the TRAPPIST-1 system.
Short cadence light curve of TRAPPIST-1 observed by K2,
de-trended with everest and
folded on the period of planet h. The orange line shows the
binned data and the red line shows the transit model
obtained from the single Spitzer observation prior to the
K2 measurements; the agreement is excellent.