Bohn, AJ, Kenworthy, MA, Ginski, C, Rieder, S, Mamajek, EE, Meshkat, T, Pecaut, MJ, Reggiani, M, Boer, JD, Keller, CU, Snik, F and Southworth, J (2020) Two Directly Imaged, Wide-orbit Giant Planets around the Young, Solar Analog TYC 8998-760-1. The Astrophysical Journal, 898 (1). ISSN 0004-637X

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Even though tens of directly imaged companions have been discovered in the past decades, the number of directly confirmed multiplanet systems is still small. Dynamical analysis of these systems imposes important constraints on formation mechanisms of these wide-orbit companions. As part of the Young Suns Exoplanet Survey we report the detection of a second planetary-mass companion around the 17 Myr-old, solar-type star TYC 8998-760-1 that is located in the Lower Centaurus Crux subgroup of the Scorpius–Centaurus association. The companion has a projected physical separation of 320 au and several individual photometric measurements from 1.1 to 3.8 microns constrain a companion mass of 6 ± 1 M Jup, which is equivalent to a mass ratio of q = 0.57 ± 0.10% with respect to the primary. With the previously detected 14 ± 3 M Jup companion that is orbiting the primary at 160 au, TYC 8998-760-1 is the first directly imaged multiplanet system that is detected around a young, solar analog. We show that circular orbits are stable, but that mildly eccentric orbits for either/both components (e > 0.1) are chaotic on gigayear timescales, implying in situ formation or a very specific ejection by an unseen third companion. Due to the wide separations of the companions TYC 8998-760-1 is an excellent system for spectroscopic and photometric follow-up with space-based observatories such as the James Webb Space Telescope.

Item Type: Article
Additional Information: The final version of this article and all relevant information regarding copyrights can be found online at;
Uncontrolled Keywords: Extrasolar gas giants ; Exoplanet astronomy ; Exoplanet detection methods ; Exoplanets ; Direct imaging
Subjects: Q Science > Q Science (General)
Q Science > QB Astronomy
Q Science > QB Astronomy > QB600 Planets. Planetology
Q Science > QC Physics
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Symplectic
Date Deposited: 05 Oct 2020 16:48
Last Modified: 12 Oct 2020 15:23

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