Skip to main content

Warm Jupiters from secular planet-planet interactions



Image: Illustration of a warm Jupiter planet. Credit: X-ray: NASA/CXC/SAO/I.Pillitteri et al; Optical: DSS

Most warm Jupiters have pericenter distances that are too large for significant orbital migration by tidal friction.


In a recent paper (Petrovich & Tremaine 2016) the authors study the possibility that the warm Jupiters are undergoing secular eccentricity oscillations excited by an outer companion (a planet or star) in an eccentric and/or mutually inclined orbit.

In this model the warm Jupiters migrate periodically, in the high-eccentricity phase of the oscillation when the pericenter distance is small, but are typically observed at much lower eccentricities.

The authors show that the steady-state eccentricity distribution of the warm Jupiters migrating by this mechanism is approximately flat, which is consistent with the observed distribution if and only if we restrict the sample to warm Jupiters that have outer companions detected by radial-velocity surveys.

The eccentricity distribution of warm Jupiters without companions exhibits a peak at low eccentricities (e≲0.2) that must be explained by a different formation mechanism.

Based on a population-synthesis study they find that high-eccentricity migration excited by an outer planetary companion (i) can account for ∼20% of the warm Jupiters and most of the warm Jupiters with e≳0.4, a fraction that is consistent with the observed population of warm Jupiters with outer companions; (ii) can produce most of the observed population of hot Jupiters, with a semimajor axis distribution that matches the observations, but fails to account adequately for ∼60% of hot Jupiters with projected obliquities ≲20°.

Thus ∼20% of the warm Jupiters and ∼60% of the hot Jupiters can be produced by high-eccentricity migration. They also provide predictions for the expected mutual inclinations and spin-orbit angles of the planetary systems with hot and warm Jupiters produced by high-eccentricity migration.

  • Petrovich & Tremaine 2016 (preprint) - Warm Jupiters from secular planet-planet interactions - (arXiv)




Etichette:

Comments

Post a Comment

Popular posts from this blog

THE HITCHCHIKER'S GUIDE TO THE LOCAL SUPERCLUSTER

Image: Virgo Supercluster. Credit: Andrew Z. Colvin The Virgo Supercluster is a region with a diameter of 33 megaparsecs (~1000 times larger the Milky Way's diameter) containing at least 100 galaxy groups and clusters.
Post a Comment
Read more

CONTAMINATION BY SUPERNOVAE IN GLOBULAR CLUSTERS

Credit: ALMA (ESO/NAOJ/NRAO)/Alexandra Angelich (NRAO/AUI/NSF) Only a small amount of the supernovae products remains trapped within globular clusters and this "catch" only occurs in the most massive cases (mass cluster ≥ 10^6 solar masses).
Post a Comment
Read more

Scientists detect comets outside our solar system

An artist’s conception of a view from within the Exocomet system KIC 3542116. Credit: Danielle Futselaar Team of professional and citizen scientists identifies tails of comets streaking past a distant star Jennifer Chu | MIT News Office Scientists from MIT and other institutions, working closely with amateur astronomers, have spotted the dusty tails of six exocomets — comets outside our solar system — orbiting a faint star 800 light years from Earth. These cosmic balls of ice and dust, which were about the size of Halley’s Comet and traveled about 100,000 miles per hour before they ultimately vaporized, are some of the smallest objects yet found outside our own solar system. The discovery marks the first time that an object as small as a comet has been detected using transit photometry, a technique by which astronomers observe a star’s light for telltale dips in intensity. Such dips signal potential transits, or crossings of planets or other objects in front of a star, ...
Post a Comment
Read more