KOI-730 as a System of Four Planets in a Chain of Resonances Daniel Fabrycky UC Santa Cruz Matthew Holman, Joshua Carter, Jason Rowe, Darin Ragozzine, William Borucki, David Koch, and the Kepler Team

Planets in Resonance Resonances are common among RV-discovered gas giants (~1 period commensurability in 3 multi systems: Wright et al. 2011, a 4:2:1 chain in GJ 876: Rivera et al. 2010) Kepler has found Neptune-size pairs especially abundant near resonances (Lissauer et al. 2011) Theories suggest the Solar System giants may have started in a resonant chain (Morbidelli et al. 2007, Thommes et al. 2008)

KOI-730: Three Pairs of First-Order Resonances 3:4:6:8 P P/P= (8) 4:3 P/P= (5) 3:2 P/P= (3) 4:3 candidateperiod (d)R p (R E )

Laplace-type resonances Involves 3 planets at once Io, Europa, & Gaynmede obey λ I -3λ E +2λ G =180°

TTVs??

Theory: Match P, T 0 coplanar mass: M p = R p 2.06 e = 0 Observed: transit times through Q8 P= d dP/dE= -1±1 s P= d dP/dE= 0±3 s P= d dP/dE= -12±12 s P= d dP/dE= 15±2 s relax

Lee & Peale 02 GJ 876 b/c Disk Migration Theory Rules-of-thumb for resonance capture: Converging and slow Low eccentricity favors first-order resonances High eccentricity favors high-order resonances

Capture into Resonance ✓ first-order resonances ✓ Laplace-type resonances ✓ moderate eccentricities ✓ increased stability

A candidate system of 4 low-mass planets on compact, resonant orbits It informs migration models: limits the speed, direction, and damping properties It’s the missing link to RV exoplanet systems, the Kepler multis, and maybe even the Solar System giants KOI-730:

Coorbital no more KOI ’s period was revised from days to twice that: days. This took it out of 1:1 resonance with KOI This was apparent even in the Q1-Q2 data and is confirmed by the data through Q8.

Stellar properties (determined by photometry, accounting for a blended companion, and fit to isochrones): Kp 15.3 mag