When
3:45 p.m., Oct. 22, 2013
Where
Kuiper Space Sciences 312
Dr. Jack Lissauer
Research Scientist
NASA Ames Research Center
Kepler's Multiple Planet Systems
Abstract:
Among the more than 2000 Kepler targets that have candidate planets, almost 25% have two or more candidate planets. While most of these objects have not yet been confirmed as true planets, several considerations strongly suggest that the vast majority of these multi-candidate systems are true multi-planet systems. Virtually all candidate systems are stable, as tested by numerical integrations (assuming amass-radius relationship based upon planets within our Solar System).The number of candidates in multiple candidate systems is more than 100 times as large as would be expected if planet candidates were distributed randomly among target stars, as would be the case for most types of false positives. Statistical studies performed on these candidate systems reveal a great deal about the architecture of planetary systems, including the typical spacing of orbits and flatness. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 and 3:2 resonances. The characteristics of some of the confirmed Kepler multi-planet systems will also be discussed.
Host: Roger Yelle
Research Scientist
NASA Ames Research Center
Kepler's Multiple Planet Systems
Abstract:
Among the more than 2000 Kepler targets that have candidate planets, almost 25% have two or more candidate planets. While most of these objects have not yet been confirmed as true planets, several considerations strongly suggest that the vast majority of these multi-candidate systems are true multi-planet systems. Virtually all candidate systems are stable, as tested by numerical integrations (assuming amass-radius relationship based upon planets within our Solar System).The number of candidates in multiple candidate systems is more than 100 times as large as would be expected if planet candidates were distributed randomly among target stars, as would be the case for most types of false positives. Statistical studies performed on these candidate systems reveal a great deal about the architecture of planetary systems, including the typical spacing of orbits and flatness. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 and 3:2 resonances. The characteristics of some of the confirmed Kepler multi-planet systems will also be discussed.
Host: Roger Yelle
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