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tokens: 17 yr, Feng et al. ( 2015 ) found strong evidence for a second planet with orbiting with a period of 15.1 ± 1.1 yr. Like GJ 628 and GJ 649, GJ 849 has nearly solar [Ti/Fe] and kinematics that skew the age posterior to younger ages. Based on this, we estimate the age of GJ 849 to be . 5.2.11. GJ 876 The planetary system around GJ 876 is a benchmark system for studying the formation and migration of planets in compact systems. GJ 876 hosts a total of four known planets, three of which are in a Laplace 1:2:4 mean-motion resonance (Rivera et al. 2010 ). The resonance is chaotic but expected to be stable on timescales of at least 1 Gyr (Rivera et al. 2010 ; Martí et al. 2013 ). The old age we infer for GJ 876 ( Gyr) suggests that such chaotic resonances can be stable for several Gyr, assuming the planets migrated into this configuration soon after their formation (Batygin et al. 2015 ). Even though the innermost planet, GJ 876 d, is not in the resonant chain with the other three planets, our old age for GJ 876 has some interesting implications for its past migration. Originally, Rivera et al. ( 2010 ) estimated that planet d orbited with an unusually high eccentricity ( e = 0.207 ± 0.055) for a planet that orbits at only 0.02 au with a period of about 2 days. Recently, Millholland et al. ( 2018 ) and Trifonov et al. ( 2018 ) reanalyzed the system by fitting dynamical N -body models to existing and new RV data. Both analyses revised the eccentricity of planet d down to values more consistent with a circular orbit. Trifonov et al. ( 2018 ) reported a best-fit eccentricity of , while Millholland et al. ( 2018 ) reported a best-fit eccentricity of e = 0.057 ± 0.039. Using the Trifonov et al. ( 2018 ) estimate for the eccentricity, we constrain the minimum Q p of GJ 876 d to be >5 × 10 5 . Such a high Q p is surprising for an ∼7 M ⊕ planet. Our minimum Q p for GJ 876 d is an order of magnitude higher than the Q p of Uranus and Neptune and three orders of magnitude greater than the Q p of terrestrial bodies. A few scenarios could explain the nonzero eccentricity of GJ 876 d. One explanation is that the planet has a peculiar structure that is very inefficient at dissipating tidal energy. Another explanation is that GJ 876 d originally orbited with a larger semimajor axis where it gravitationally interacted with the outer three planets and, at some point in its history, fell out of a chaotic resonance with the outer planets and migrated in. A third scenario is that there is another, unseen planet in the system that is gravitationally interacting with GJ 876 d. We note that the eccentricity of GJ 876 d has undergone downward revision recently. If additional observations in future studies lead to further downward revision and the conclusion that the orbit is essentially circular, it may not be necessary to invoke one of the above scenarios to explain the orbit of GJ 876 d. In that case, our minimum Q p will be overestimated. However, given its proximity