A CHEOPS-enhanced view of the HD3167 system

Abstract

Much remains to be understood about the nature of exoplanets smaller than Neptune, most of which have been discovered in compact multi-planet systems. With its inner ultra-short period planet b aligned with the star and two larger outer planets d-c on polar orbits, the multi-planet system HD 3167 features a peculiar architecture and offers the possibility to investigate both dynamical and atmospheric evolution processes. To this purpose we combined multiple datasets of transit photometry and radial velocimetry (RV) to revise the properties of the system and inform models of its planets. This effort was spearheaded by CHEOPS observations of HD 3167b, which appear inconsistent with a purely rocky composition despite its extreme irradiation. Overall the precision on the planetary orbital periods are improved by an order of magnitude, and the uncertainties on the densities of the transiting planets b and c are decreased by a factor of 3. Internal structure and atmospheric simulations draw a contrasting picture between HD 3167d, likely a rocky super-Earth that lost its atmosphere through photo-evaporation, and HD 3167c, a mini-Neptune that kept a substantial primordial gaseous envelope. We detect a fourth, more massive planet on a larger orbit, likely coplanar with HD 3167d-c. Dynamical simulations indeed show that the outer planetary system d-c-e was tilted, as a whole, early in the system history, when HD 3167b was still dominated by the star influence and maintained its aligned orbit. RV data and direct imaging rule out that the companion that could be responsible for the present-day architecture is still bound to the HD\,3167 system. Similar global studies of multi-planet systems will tell how many share the peculiar properties of the HD3167 system, which remains a target of choice for follow-up observations and simulations.

22 pages, 23 pages, accepted for publication in A&A (18 August 2022). Updated author list in new version

References in corpus (38)

• The Gaia mission
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Gaia Early Data Release 3: Parallax bias versus magnitude, colour, and position
• A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission
• Growth Model Interpretation of Planet Size Distribution
• Can we constrain interior structure of rocky exoplanets from mass and radius measurements?
• A new code for automatic determination of equivalent widths: Automatic Routine for line Equivalent widths in stellar Spectra (ARES)
• The CHEOPS mission
• CLES, Code Liegeois d'Evolution Stellaire
• Revisited Mass-Radius relations for exoplanets below 120 Earth masses
• Stellar Winds on the Main-Sequence II: the Evolution of Rotation and Winds
• ARES v2 - new features and improved performance
• Chemistry of Silicate Atmospheres of Evaporating Super-Earths
• Six transiting planets and a chain of Laplace resonances in TOI-178
• Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimum
• Theoretical Emission Spectra of Atmospheres of Hot Rocky Super-Earths
• Revising the ages of planet-hosting stars
• Three Years of HARPS-N High-Resolution Spectroscopy and Precise Radial Velocity Data for the Sun
• The HARPS search for southern extra-solar planets XXXV. The interesting case of HD41248: stellar activity, no planets?
• SWEET-Cat 2.0: The Cat just got SWEETer; Higher quality spectra and precise parallaxes from GAIA eDR3
• Three's Company: An additional non-transiting super-Earth in the bright HD 3167 system, and masses for all three planets
• Gas composition of main volatile elements in protoplanetary discs and its implication for planet formation
• CHEOPS observations of the HD 108236 planetary system: A fifth planet, improved ephemerides, and planetary radii
• Magma oceans and enhanced volcanism on TRAPPIST-1 planets due to induction heating
• The transiting multi-planet system HD3167: a 5.7 MEarth Super-Earth and a 8.3 MEarth mini-Neptune
• Two Small Planets Transiting HD 3167
• The Rossiter-McLaughlin effect Revolutions: An ultra-short period planet and a warm mini-Neptune on perpendicular orbits
• The Na I D resonance lines in main sequence late-type stars
• WASP-186 and WASP-187: two hot Jupiters discovered by SuperWASP and SOPHIE with additional observations by TESS
• Speckle Imaging Excludes Low-Mass Companions Orbiting the Exoplanet Host Star TRAPPIST-1
• The atmosphere and architecture of WASP-189 b probed by its CHEOPS phase curve
• Compact planetary systems perturbed by an inclined companion: II. Stellar spin-orbit evolution
• Reinvestigating $\alpha$ Cen AB in light of asteroseismic forward and inverse methods
• 3D MHD Simulations of Accretion onto Stars with Tilted Magnetic and Rotational Axes
• Close-in sub-Neptunes reveal the past rotation history of their host stars: atmospheric evolution of planets in the HD3167 and K2-32 planetary systems
• Transmission spectroscopy for the warm sub-Neptune HD3167c: evidence for molecular absorption and a possible high metallicity atmosphere
• ARES IV: Probing the atmospheres of the two warm small planets HD 106315 c and HD 3167 c with the HST/WFC3 camera
• The Origin of Systems of Tightly Packed Inner Planets with Misaligned, Ultra-Short-Period Companions

Cited by in corpus (5)

• Cold Jupiters and improved masses in 38 Kepler and K2 small planet systems from 3661 HARPS-N radial velocities. No excess of cold Jupiters in small planet systems
• Shallower radius valley around low-mass hosts: Evidence for icy planets, collisions or high-energy radiation scatter
• Dark skies of the slightly eccentric WASP-18 b from its optical-to-infrared dayside emission
• Sculpting of Exoplanetary Systems Driven by a Misaligned Disk and Stellar Oblateness: Origin of Perpendicular Orbits in HD 3167
• Evidence for an Atmosphere on the Ultra-Short Period super-Earth HD 3167 b