Misalignment of terrestrial circumbinary planets as an indicator of their formation mechanism

Abstract

Circumbinary gas disks are often observed to be misaligned to the binary orbit suggesting that planet formation may proceed in a misaligned disk. With N-body simulations we consider the formation of circumbinary terrestrial planets from a particle disk that is initially misaligned. We find that if terrestrial planets form in this way, in the absence of gas, they can only form close to coplanar or close to polar to the binary orbit. Planets around a circular binary form coplanar while planets around an eccentric binary can form coplanar or polar depending on the initial disk misalignment and the binary eccentricity. The more massive a terrestrial planet is, the more aligned it is (to coplanar or polar) since it has undergone more mergers that lead on average to smaller misalignment angles. Nodal precession of particle disks with very large initial inclinations lead to high mutual inclinations between the particles. This produces high relative velocities between particles that leads to mass ejections that can completely inhibit planet formation. Misaligned terrestrial circumbinary planets may be able to form in the presence of a misaligned circumbinary gas disk that may help to nodally align the particle orbits and maintain the inclination of the planets during their formation.

Accepted for publication in ApJL. 9 pages, 3 figures

References in corpus (28)

• On the diversity and statistical properties of protostellar discs
• On the Abundance of Circumbinary Planets
• Misaligned Disks in the Binary Protostar IRS 43
• Planets Transiting Non-Eclipsing Binaries
• Terrestrial Planet Formation Surrounding Close Binary Stars
• Relative velocities among accreting planetesimals in binary systems: the circumbinary case
• Polar alignment of a protoplanetary disk around an eccentric binary
• Inclination Evolution of Protoplanetary Disks Around Eccentric Binaries
• The dispersal of protoplanetary disks around binary stars
• Uncovering Circumbinary Planetary Architectural Properties from Selection Biases
• Planet formation in stellar binaries II: overcoming the fragmentation barrier in alpha Centauri and gamma Cephei-like systems
• The BEBOP radial-velocity survey for circumbinary planets I. Eight years of CORALIE observations of 47 single-line eclipsing binaries and abundance constraints on the masses of circumbinary planets
• Linear Analysis of the Evolution of Nearly Polar Low Mass Circumbinary Discs
• Spiral Arms, Infall, and Misalignment of the Circumbinary Disk from the Circumstellar Disks in the Protostellar Binary System L1551 NE
• ALMA observations of a high-density core in Taurus: dynamical gas interaction at the possible site of a multiple star formation
• Secular and tidal evolution of circumbinary systems
• Alignment of a circumbinary disc around an eccentric binary with application to KH 15D
• Circumbinary planets II - when transits come and go
• Parking planets in circumbinary discs
• Polar planets around highly eccentric binaries are the most stable
• The Effect of Planets Beyond the Ice Line on the Accretion of Volatiles by Habitable-Zone Rocky Planets
• Resolved Multifrequency Radio Observations of GG Tau
• Flyby-induced misalignments in planet-hosting discs
• Formation of polar terrestrial circumbinary planets
• Running The Gauntlet -- Survival of Small Circumbinary Planets Migrating Through Destabilising Resonances
• Terrestrial planet formation in a circumbinary disc around a coplanar binary
• Collisional fragmentation and bulk composition tracking in REBOUND
• Double-peaked OI profile: a likely signature of the gaseous ring around KH 15D

Cited by in corpus (6)

• Evidence for a polar circumbinary exoplanet orbiting a pair of eclipsing brown dwarfs
• Polar alignment of a massive retrograde circumbinary disc around an eccentric binary
• Misaligned circumbinary disks as efficient progenitors of interstellar asteroids
• Coplanar circumbinary planets can be unstable to large tilt oscillations in the presence of an inner polar planet
• Orbital stability of two circumbinary planets around misaligned eccentric binaries
• Orbits of the TOI-1338 and TIC-172900988 systems