New Dynamical State and Habitability of the HD 45364 Planetary System
arXiv:2209.00120 · doi:10.3847/1538-3881/ac8d63
Abstract
Planetary systems with multiple giant planets provide important opportunities to study planetary formation and evolution. The HD 45364 system hosts two giant planets that reside within the Habitable Zone (HZ) of their host star and was the first system discovered with a 3:2 mean motion resonance (MMR). Several competing migration theories with different predictions have previously provided explanations regarding the observed resonance through dynamical simulations that utilized limited data. Here, over ten years since the original discovery, we revisit the system with a substantially increased radial velocity (RV) sample from HARPS and HIRES that significantly extend the observational baseline. We present the revised orbital solutions for the two planets using both Keplerian and dynamical models. Our RV models suggest orbits that are more circular and separated than those previously reported. As a result, predicted strong planet-planet interactions were not detected. The system dynamics were reanalyzed, and the planet pair was found to exhibit apsidal behavior of both libration and circulation, indicating a quasi-resonance state rather than being truly in MMR. The new orbital solution and dynamical state of the system confirm migration models that predicted near circular orbits as the preferred scenario. We also study the habitability prospects of this system and found that an additional Earth-mass planet and exomoons in the HZ are possible. This work showcases the importance of continued RV observation and its impact on our knowledge of the system's dynamical history. HD 45364 continues to be an interesting target for both planetary formation and habitability studies.
16 pages, 10 figures, accepted for publication in the Astronomical Journal
References in corpus (28)
- The Transiting Exoplanet Survey Satellite
- The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
- Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
- Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
- Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
- Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581
- A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
- Exotic Earths: Forming Habitable Worlds with Giant Planet Migration
- A Catalog of Kepler Habitable Zone Exoplanet Candidates
- Formation, Habitability, and Detection of Extrasolar Moons
- Stellar activity mimics a habitable-zone planet around Kapteyn's star
- High eccentricity planets from the Anglo-Australian Planet Search
- Mean motion resonances from planet-planet scattering
- HD45364, a pair of planets in a 3:2 mean motion resonance
- Color difference makes a difference: four planet candidates around tau Ceti
- Disentangling Planets and Stellar Activity for Gliese 667C
- The Search for other Earths: limits on the giant planet orbits that allow habitable terrestrial planets to form
- The Young Suns Exoplanet Survey: Detection of a wide orbit planetary mass companion to a solar-type Sco-Cen member
- Behavior of Apsidal Orientations in Planetary Systems
- The Second Discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) Program: A Cold Wide-Orbit Exoplanet around a Young Field M Dwarf at 10.9 pc
- Innocent Bystanders: Orbital Dynamics of Exomoons during Planet-Planet Scattering
- The Pan-Pacific Planet Search. VIII. Complete results and the occurrence rate of planets around low-luminosity giants
- Application of Orbital Stability and Tidal Migration Constraints for Exomoon Candidates
- In the Presence of a Wrecking Ball: Orbital Stability in the HR 5183 System
- Dynamical Packing in the Habitable Zone: The Case of Beta CVn
- A Comprehensive Characterization of the 70 Virginis Planetary System
- The GAPS Programme with HARPS-N@TNG XII: Characterization of the planetary system around HD108874
- Orbital Dynamics and the Evolution of Planetary Habitability in the AU Mic System