Can Planets Exist in the Habitable Zone of 55-Cancri?

The aim of our study is to explore the possible existence of Earth-mass planets in the habitable zone of 55~Cancri, an effort pursued based on detailed orbital stability simulations.

This star is known to possess (at least) five planets with masses ranging between super-Earth and Jupiter-type. Additionally, according to observational constraints, there is a space without planets between ∼0.8~au and ∼5.7~au, noting that the inner part of this gap largely coincides with 55~Cnc’s habitable zone — a sincere motivation for the search of potentially habitable planets. It has previously been argued that terrestrial habitable planets are able to exist in the 55~Cnc system, including a planet at ∼1.5~au. We explore this possibility through employing sets of orbital integrations and assuming an integration time of 50~Myr.

We found that the possibility of Earth-mass planets in the system’s habitable zone strongly depends on the adopted system parameters, notably the eccentricity of 55~Cnc-f, which is controversial as both a high value (e∼0.32) and a low value (e∼0.08) have previously been deduced. In case that the low value is adopted (together with other updates for the system parameters), the more plausible and most recent value, Earth-mass planets would be able to exist in the gap between 1.0~au and 2.0~au, thus implying the possibility of habitable system planets. Thus, 55~Cnc should be considered a favorable target for future habitable planet search missions.

Suman Satyal, Manfred Cuntz
(Submitted on 25 Feb 2019)

Comments: Accepted by the Publications of the Astronomical Society of Japan (PASJ); 23 pages, 6 figures, 3 tables
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1902.09613 [astro-ph.EP] (or arXiv:1902.09613v1 [astro-ph.EP] for this version)
Submission history
From: Suman Satyal
[v1] Mon, 25 Feb 2019 20:57:56 UTC (16,546 KB)
https://arxiv.org/abs/1902.09613
Astrobiology