{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"bf5fe48e47c52594633dc2cbbfab516be20ee7089f083826a28662dbbdec5e36","created":"2026-10-03T07:17:56Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"6e27b453ecfec3a7071cd1b7fbfceec76f8befc5e526ae4d1ab4ecbfb40a551b","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"astro.system-architectures.resonant-chain-breaking","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Planets migrating through a gas disk tend to lock into resonances, where their orbital periods form simple ratios such as 3:2. Yet most observed multiplanet systems are not in resonance, so most chains must later break apart, and models do not break enough of them.","posed_since":"2017","precise":"Disk migration of super-Earths produces chains of mean-motion resonances, but only a small fraction of Kepler multiplanet pairs are in or near first-order resonance. Izidoro et al. 2017 (arXiv:1703.03634) found that at least 75 percent (probably 90-95 percent) of chains must become unstable after disk dispersal to match Kepler period ratios, while only 50-60 percent did in their simulations. Determine the mechanism that breaks the required fraction: self-driven instability, perturbations from outer giants, stellar tides or disk-dispersal effects, reproducing the observed period-ratio distribution and resonant fraction.","problem_ref":null,"references":"","settled_by":"Population-level N-body simulations from disk migration through Gyr evolution that reproduce the Kepler period-ratio distribution, multiplicity and resonant fraction versus age.","status_note":"","title":"Why are most compact multiplanet systems not in orbital resonance?","topic_ref":"705ebcb3477b591f7d0888a668b37821e2d427d0c8c498a50e19534d5adf0f6f"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"616645388f19972b9669269f1b9aa1881597a2e0187d1767c09b2cbf1870ea8c","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"0cac54d59a7a92b14fc1d47a49c4e30d8df1b50e18bb9e3c914c98b212663a03","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"bXShX_OGIh3o31eDT-5xT8M1AmXhP96UMY-56ZbwqGjPWqohY2YshticTSbwyP3Y-7is24T_coSSACTwsFjWBA"},"schema":"pubphys.envelope/1"},"record_hash":"616645388f19972b9669269f1b9aa1881597a2e0187d1767c09b2cbf1870ea8c","leaf_index":634}