no normal ss final remarks why disk migration not

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Unformatted text preview: secular interactions... No “Normal” SS Final remarks Why disk migration not good enough? -The standard theory of tidal migration (type I and II) produces planets that are aligned with the star, whereas observations show that this is often not the case - we see hot Jupiters with correlation between strength of planet-star tidal interaction and obliquity → migrate to high obliquity, and then tidally align more with the star (Albrecht et al 2012 c) How common are retrograde planets in our sample of exoplanets? -About 20% of known exoplanets are HJs - Near 25% of HJs discovered have retrograde orbits. - A handful of very recent multi-planet systems found. In regards to our solar system - We now know that multi-planet systems can have retrograde planets - Small planets are less fit to have strong tidal interactions with host star thus orbital alignment may be more primitive. - Temperature of the sun may exclude retrograde systems. How would different mechanisms affect where we find retrograde planets? - Does the parent star have a companion? - What is the temperature of the parent star? - Is it a multiple planet system? - Mostly HJs? How would different mechanisms affect where we find retrograde planets? - Does the parent star have a companion? Kozai, warped disk - What is the temperature of the parent star? Tidal dissipation realignment - Is it a multiple planet system? Planet-Planet scattering, probably not Kozai - Mostly HJs? Long timescale tidal interactions? How can we make progress in this field? - Are retrograde orbits exclusive to HJs? No, but are they more prevalent in HJs? - Look for unusual obliquities in multiple planet systems (Albrecht 2013) - Utilize alternative methods to measure obliquities - Statistical sample...
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This document was uploaded on 04/05/2014.

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