Alien solar system boasts tightly spaced planets, unusual orbits July 21, 2016 by Adam Lowenstein Please Register or Log in to view the hidden image! This GIF shows the synchronized orbit of the Kepler-80 system. Credit: Florida Institute of Technology Tightly spaced planets inside an alien solar system known as Kepler-80 boast a rare orbital configuration. The study was led by Mariah MacDonald as an undergraduate with Darin Ragozzine, an assistant professor of physics and space sciences, both at Florida Institute of Technology. The unusual planetary array highlighted in the study deepens the ongoing examination of similar systems known as STIPs – Systems with Tightly-spaced Inner Planets – and contributes to the understanding of how Earth formed. Read more at: http://phys.org/news/2016-07-alien-solar-tightly-spaced-planets.html#jCp
http://adsabs.harvard.edu/abs/2015DPS....4750105M Abstract: Kepler has discovered hundreds of multi-transiting systems which hold tremendous potential both individually and collectively for understanding the formation and evolution of planetary systems. Many of these systems are quite compact, containing 3-7 relatively small planets with periods less than 100 days; these are known as Systems with Tightly-packed Inner planets, or STIPs. One ultra-compact STIP is KOI-500/Kepler-80, a planetary system containing five transiting planets ranging in size from 1.5 to 2.8 times the radius of the Earth that orbit in a tightly-packed configuration with periods between 1 and 10 days. In addition to its close packedness, the outer four planets are in a unique dynamical configuration with two interconnected three-body resonances. Using transit timing variations (TTVs) caused by the gravitational perturbations, we perform a fully self-consistent dynamical analysis of the system, finding best-fit masses for the outer four planets to be each around five Earth masses. We also performed extensive testing of synthetic systems, and have determined that eccentricities cannot be reliably detected, but that assuming circular orbits does not significantly affect the mass estimates. We will present the inferred properties for Kepler-80 and discuss these results in context of (ultra-compact) STIPs and the small planet mass-radius relation.
