Measures of exoplanet bulk densities indicate that small exoplanets with radius less than 3
Earth radii (R⊕) range from low-density sub-Neptunes containing volatile elements to
higher-density rocky planets with Earth-like or iron-rich (Mercury-like) compositions. Such
astonishing diversity in observed small exoplanet compositions may be the product of
different initial conditions of the planet-formation process or different evolutionary paths that
altered the planetary properties after formation. Planet evolution may be especially affected …

… Supplementary Figure 1: Transits of the Kepler-107 planets. Phase-folded transits of the four
Kepler-107 planets with the best-fit model (red solid line) and residuals. For illustration
purposes, data were binned in phase bins of 30, 45, 85, and 110 s for planets b, c, d, and e. …
Supplementary Figure 4: Peakbagging fit for Kepler-107. The power density spectrum centred
on the region of excess power from solar-like oscillations is shown in grey, with a 1μHz
smoothed version overlain in black. The best fitting model from the peakbagging is shown in red. …