Five Planets Orbiting 55 Cancri

A dynamical perspective on additional planets in 55 Cancri

Five planets are known to orbit the star 55 Cancri. The recently-discovered planet f at 0.78 AU (Fischer et al. 2008) is located at the inner edge of a previously-identified stable zone that separates the three close-in planets from planet d at 5.9 AU. Here we map the stability of the orbital space between planets f and d using a suite of n-body integrations that include an additional, yet-to-b...

Dynamics of the 55 Cancri System

Recent studies of the 55 Cancri system suggest the existence of three planets with periods of ∼15 days, ∼45 days, and ∼5500 days (Marcy et al. 2002). The inner two planets are near the 3:1 mean motion commensurability and it is likely that these two planets became trapped in the resonance while farther from the star and migrated together. As the innermost planet begins to dissipate energy throu...

Two Earth - sized planets orbiting

Three planets orbiting Wolf 1061

We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf 1061 (GJ 628). We detect a 1.36 M⊕ minimum-mass planet with an orbital period P = 4.888 d (Wolf 1061b), a 4.25 M⊕ minimum-mass planet with orbital period P = 17.867 d (Wolf 1061c), and a likely 5.21 M⊕ minimum-mass planet with orbital period P = 67.274 d (Wolf 1061d). All of the planets are of sufficiently low mass...

Frequency map analysis of the 3/1 resonance between planets b and c in the 55 Cancri system

We investigate the dynamical stability of the 3/1 resonant planets b and c in the extrasolar planetary system around 55 Cancri by applying Laskar’s frequency map analysis. We find that the region with low diffusion speed extends to high eccentricity for both planets and that the observed system is deeply embedded in this region. The dynamics while in resonance and the influence of planet e on t...