Daniel
Neptune-Mass
Number of posts : 315
Registration date : 2009-11-14
 | | Subject: Discovery of a Jupiter Analog Misaligned to the Inner Planetary System in HD 73344 19th August 2024, 9:49 pm | |
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- We present the discovery of a Jupiter-like planet, HD 73344 d (md=2.55+0.56−0.46 MJ, ad=6.70+0.25−0.26 AU, ed=0.18+0.14−0.12) based on 27-year radial velocity observations. HD 73344 also hosts a compact inner planetary system, including a transiting sub-Neptune HD 73344 b (Pb=15.61 days, rb=2.88+0.08−0.07 R⊕) and a non-transiting Saturn-mass planet (Pc=65.936 days, mcsinic=0.36+0.02−0.02 MJ). By analyzing TESS light curves, we identified a stellar rotation period of 9.03±1.3 days. Combining this with vsini∗ measurements from stellar spectra, we derived a stellar inclination of 63.6+17.4−16.5 deg. Furthermore, by combining radial velocities and Hipparcos-Gaia astrometric acceleration, we characterized the three-dimensional orbit of the outer giant planet and constrained its mutual inclination relative to the innermost transiting planet to be 46<ΔIbd<134 deg (1σ) and 20<ΔIbd<160 deg (2σ), strongly disfavoring coplanar architectures. Our analytical calculations and N-body simulation reveal that the two inner planets are strongly coupled with each other and undergo nodal precession together around the orbital axis of the giant planet. During nodal precession, the orbital inclination of inner planets oscillate with time and therefore become misaligned relative to the stellar spin axis. The formation of such systems suggests a history of planet-planet scattering or misalignment between the inner and outer components of protoplanetary disks. The upcoming release of Gaia DR4 will uncover more systems similar to HD 73344 and enable the study of the flatness of exoplanet systems with a mixture of inner and outer planetary systems on a statistical level
https://arxiv.org/abs/2408.09614 | |
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