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arXiv · 1107.1936

The 55 Cancri System: Fundamental Stellar Parameters, Habitable Zone Planet, and Super-Earth Diameter

K. von Braun·T. S. Boyajian·T. A. ten Brummelaar·G. T. van Belle·S. R. Kane·D. R. Ciardi·M. Lopez-Morales·H. A. McAlister·G. Schaefer·S. T. Ridgway·L. Sturmann·J. Sturmann·R. White·N. H. Turner·C. Farrington·P. J. Goldfinger
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Abstract

The bright star 55 Cancri is known to host five planets, including a transiting super-Earth. We use the CHARA Array to directly determine the following of 55 Cnc's stellar astrophysical parameters: $R=0.943 \pm 0.010 R_{\odot}$, $T_{\rm EFF} = 5196 \pm 24$ K. Planet 55 Cnc f ($M \sin i = 0.155 M_{Jupiter}$) spends the majority of the duration of its elliptical orbit in the circumstellar habitable zone (0.67--1.32 AU) where, with moderate greenhouse heating, it could harbor liquid water. Our determination of 55 Cancri's stellar radius allows for a model-independent calculation of the physical diameter of the transiting super-Earth 55 Cnc e ($\simeq 2.1 R_{\earth}$), which, depending on the assumed literature value of planetary mass, implies a bulk density of 0.76 $\rho_{\earth}$ or 1.07 $\rho_{\earth}$.

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K. von Braun, T. S. Boyajian, T. A. ten Brummelaar, G. T. van Belle, S. R. Kane, D. R. Ciardi, M. Lopez-Morales, H. A. McAlister, G. Schaefer, S. T. Ridgway, L. Sturmann, J. Sturmann, R. White, N. H. Turner, C. Farrington, P. J. Goldfinger. 2011-07-11. The 55 Cancri System: Fundamental Stellar Parameters, Habitable Zone Planet, and Super-Earth Diameter. https://arxiv.org/abs/1107.1936

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