The Pan-Pacific Planet Search. VII. The Most Eccentric Planet Orbiting a Giant Star

Monthly Notices of the Royal Astronomical Society

Clark

Zhao

et al. 2019

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We examine eight known single-eccentric planetary systems in light of recently released large data archives and new analysis techniques. For four of these systems (HD 7449, HD 65216, HD 89744, HD 92788) we find evidence for additional long-period companions. HD 65216c is a Jupiter analog, with a period of 14.7 yr, e = 0.18, and m sin i of 2M Jup , whilst the remaining candidate companions move on as-yet-incomplete orbits. Our results highlight the importance of revisiting the analysis of known exoplanetary systems when new data become available, particularly given the possibility that poorly-sampled data might previously have led to the detection of a 'false-positive' single eccentric planet, when the system in question actually contains two (or more) planets on near-circular orbits.

Section: Hd 7449mentioning

confidence: 62%

Truly eccentric – I. Revisiting eight single-eccentric planetary systems

Monthly Notices of the Royal Astronomical Society

Clark

Zhao

et al. 2019

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“…Butler et al 1997;Hellier et al 2011;Wright et al 2012), as well as planets moving on orbits so eccentric that they more closely resemble the orbits of comets than the planets in our own backyard (e.g. Wittenmyer et al 2007;Tamuz et al 2008;Wittenmyer et al 2017b). We also found many systems with multiple planets moving on orbits locked in mutual meanmotion resonance (e.g.…”

Section: Introductionmentioning

confidence: 97%

Truly eccentric – II. When can two circular planets mimic a single eccentric orbit?

Monthly Notices of the Royal Astronomical Society

Bergmann

Horner

et al. 2019

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When, in the course of searching for exoplanets, sparse sampling and noisy data make it necessary to disentangle possible solutions to the observations, one must consider the possibility that what appears to be a single eccentric Keplerian signal may in reality be attributed to two planets in near-circular orbits. There is precedent in the literature for such outcomes, whereby further data or new analysis techniques reveal hitherto occulted signals. Here, we perform suites of simulations to explore the range of possible two-planet configurations that can result in such confusion. We find that a single Keplerian orbit with e > ∼ 0.5 can virtually never be mimicked by such deceptive system architectures. This result adds credibility to the most eccentric planets that have been found to date, and suggests that it could well be worth revisiting the catalogue of moderately eccentric 'confirmed' exoplanets in the coming years, as more data become available, to determine whether any such deceptive couplets are hidden in the observational data.

“…Wolszczan, & Frail 1992;Mayor & Queloz 1995;Wright et al 2012), to the highly eccentric worlds found by radial velocity surveys (e.g. Jones et al 2006;Tamuz et al 2008;Wittenmyer et al 2017c), as more planets have been that truly resemble our own (e.g. Marcy et al 2002;Wittenmyer et al 2014bWittenmyer et al , 2017aAgnew et al 2018;Buchhave et al 2018).…”

Section: Introductionmentioning

confidence: 98%

Cool Jupiters greatly outnumber their toasty siblings: occurrence rates from the Anglo-Australian Planet Search

Monthly Notices of the Royal Astronomical Society

Wang

Horner

et al. 2019

Self Cite

129

Our understanding of planetary systems different to our own has grown dramatically in the past 30 years. However, our efforts to ascertain the degree to which the Solar system is abnormal or unique have been hindered by the observational biases inherent to the methods that have yielded the greatest exoplanet hauls. On the basis of such surveys, one might consider our planetary system highly unusual -but the reality is that we are only now beginning to uncover the true picture. In this work, we use the full eighteen-year archive of data from the Anglo-Australian Planet Search to examine the abundance of 'Cool Jupiters' -analogs to the Solar system's giant planets, Jupiter and Saturn. We find that such planets are intrinsically far more common through the cosmos than their siblings, the hot Jupiters. We find that the occurrence rate of such 'Cool Jupiters' is 6.73 +2.09 −1.13 %, almost an order of magnitude higher than the occurrence of hot Jupiters (at 0.84 +0.70 −0.20 %). We also find that the occurrence rate of giant planets is essentially constant beyond orbital distances of ∼1 au. Our results reinforce the importance of legacy radial velocity surveys for the understanding of the Solar system's place in the cosmos.