Nearly polar orbit of the sub-Neptune HD 3167 c. Constraints on the dynamical history of a multi-planet system (original) (raw)
NASA/ADS
;
- Hébrard, G. ;
- Lecavelier des Étangs, A. ;
- Petit, A. C. ;
- Bourrier, V. ;
- Laskar, J. ;
- König, P. -C. ;
- Correia, A. C. M.
Abstract
Aims: We present the obliquity measurement, that is, the angle between the normal angle of the orbital plane and the stellar spin axis, of the sub-Neptune planet HD 3167 c, which transits a bright nearby K0 star. We study the orbital architecture of this multi-planet system to understand its dynamical history. We also place constraints on the obliquity of planet d based on the geometry of the planetary system and the dynamical study of the system.
Methods: New observations obtained with HARPS-N at the Telescopio Nazionale Galileo (TNG) were employed for our analysis. The sky-projected obliquity was measured using three different methods: the Rossiter-McLaughlin anomaly, Doppler tomography, and reloaded Rossiter-McLaughlin techniques. We performed the stability analysis of the system and investigated the dynamical interactions between the planets and the star.
Results: HD 3167 c is found to be nearly polar with sky-projected obliquity, λ = -97°± 23°. This misalignment of the orbit of planet c with the spin axis of the host star is detected with 97% confidence. The analysis of the dynamics of this system yields coplanar orbits of planets c and d. It also shows that it is unlikely that the currently observed system can generate this high obliquity for planets c and d by itself. However, the polar orbits of planets c and d could be explained by the presence of an outer companion in the system. Follow-up observations of the system are required to confirm such a long-period companion.
Publication:
Astronomy and Astrophysics
Pub Date:
November 2019
DOI:
arXiv:
Bibcode:
Keywords:
- techniques: radial velocities;
- planets and satellites: fundamental parameters;
- planet-star interactions;
- planets and satellites: individual: HD 3167;
- Astrophysics - Earth and Planetary Astrophysics
E-Print:
13 pages, 11 figures, 2 tables. Accepted for publication in A&