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تسجيل مستخدم جديدPrecise radial velocities of giant stars XIII. A second Jupiter orbiting in 4:3 resonance in the 7 CMa system
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We report the discovery of a second planet orbiting the K giant star 7 CMa based on 166 high-precision radial velocities obtained with Lick, HARPS, UCLES and SONG. The periodogram analysis reveals two periodic signals of approximately 745 and 980 d, associated to planetary companions. A double-Keplerian orbital fit of the data reveals two Jupiter-like planets with minimum masses $m_bsin i sim 1.9 ,mathrm{M_{J}}$ and $m_csin i sim 0.9 ,mathrm{M_{J}}$, orbiting at semi-major axes of $a_b sim 1.75,mathrm{au}$ and $a_c sim 2.15,mathrm{au}$, respectively. Given the small orbital separation and the large minimum masses of the planets close encounters may occur within the time baseline of the observations, thus, a more accurate N-body dynamical modeling of the available data is performed. The dynamical best-fit solution leads to collision of the planets and we explore the long-term stable configuration of the system in a Bayesian framework, confirming that 13% of the posterior samples are stable for at least 10 Myr. The result from the stability analysis indicates that the two-planets are trapped in a low-eccentricity 4:3 mean-motion resonance. This is only the third discovered system to be inside a 4:3 resonance, making it very valuable for planet formation and orbital evolution models.
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Context: For over 12 yr, we have carried out a precise radial velocity survey of a sample of 373 G and K giant stars using the Hamilton Echelle Spectrograph at Lick Observatory. There are, among others, a number of multiple planetary systems in our s
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Radial-velocity variations of the K giant star Aldebaran ($alpha$ Tau) were first reported in the early 1990s. After subsequent analyses, the radial-velocity variability with a period of $sim 629,mathrm{d}$ has recently been interpreted as caused by
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