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.
Keywords
Cite
@article{arxiv.2209.06937,
title = {A CHEOPS-enhanced view of the HD3167 system},
author = {V. Bourrier and A. Deline and A. Krenn and J. A. Egger and A. C. Petit and L. Malavolta and M. Cretignier and N. Billot and C. Broeg and H. -G. Florén and D. Queloz and Y. Alibert and A. Bonfanti and A. S. Bonomo and J. -B. Delisle and O. D. S. Demangeon and B. -O. Demory and X. Dumusque and D. Ehrenreich and R. D. Haywood and S. B Howell and M. Lendl and A. Mortier and G. Nigro and S. Salmon and S. G. Sousa and T. G. Wilson and V. Adibekyan and R. Alonso and G. Anglada and T. Bárczy and D. Barrado y Navascues and S. C. C. Barros and W. Baumjohann and M. Beck and W. Benz and F. Biondi and X. Bonfils and A. Brandeker and J. Cabrera and S. Charnoz and Sz. Csizmadia and A. Collier Cameron and M. Damasso and M. B. Davies and M. Deleuil and L. Delrez and L. Di Fabrizio and A. Erikson and A. Fortier and L. Fossati and M. Fridlund and D. Gandolfi and M. Gillon and M. Güdel and K. Heng and S. Hoyer and K. G. Isaak and L. L. Kiss and J. Laskar and A. Lecavelier des Etangs and V. Lorenzi and C. Lovis and D. Magrin and A. Massa and P. F. L. Maxted and V. Nascimbeni and G. Olofsson and R. Ottensamer and I. Pagano and E. Pallé and G. Peter and G. Piotto and D. Pollacco and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and N. C. Santos and G. Scandariato and D. Ségransan and A. E. Simon and A. M. S. Smith and M. Steller and Gy. M. Szabó and N. Thomas and S. Udry and V. Van Grootel and F. Verrecchia and N. Walton and T. Beck and M. Buder and F. Ratti and B. Ulmer and V. Viotto},
journal= {arXiv preprint arXiv:2209.06937},
year = {2022}
}
Comments
22 pages, 23 pages, accepted for publication in A&A (18 August 2022). Updated author list in new version