Precise radial velocities of giant stars: XIII. A second Jupiter orbiting in 4:3 resonance in the 7 CMa system
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 with planetary companions. A double-Ke...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
06 November 2019
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| In: |
Astronomy and astrophysics
Year: 2019, Volume: 631 |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/201936464 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1051/0004-6361/201936464 Verlag: https://www.aanda.org/articles/aa/abs/2019/11/aa36464-19/aa36464-19.html 
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| Author Notes: | R. Luque, T. Trifonov, S. Reffert, A. Quirrenbach, M.H. Lee, S. Albrecht, M. Fredslund Andersen, V. Antoci, F. Grundahl, C. Schwab, and V. Wolthoff |
| Summary: | 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 with planetary companions. A double-Keplerian orbital fit of the data reveals two Jupiter-like planets with minimum masses mb sin i ~ 1.9 MJ and mc sini~ 0.9 MJ, orbiting at semimajor axes of ab ~ 1.75 au and ac ~ 2.15 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 this discovery very valuable for planet formation and orbital evolution models. |
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| Item Description: | Gesehen am 12.02.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/201936464 |