10-14-2025, 08:59 PM
(This post was last modified: 10-14-2025, 08:59 PM by AstroChara.)
Today's arXiv day brings us a preprint of the 55 Cancri system. It refined the properties of the known planets around the primary star (A; Copernicus), and proposed a sixth planet which doesn't look that stable when placed next to Lipperhey...but then again Lipperhey is a dubious planet, and this paper came out too soon to cite the earlier preprint that doubted it.
More interestingly, this work also checked RV data of the secondary star in this system (B), and found two planets: 55 Cancri B b and B c, superterran/subneptunian worlds with the following parameters:
55 Cancri B b
- Semi-major axis: 0.044 au
- Orbital period: 6.7994 days
- Mass: 3.5 ± 0.8 MEarth
55 Cancri B c
- Semi-major axis: 0.13 au
- Orbital period: 33.747 days
- Mass: 5.3 ± 1.4 MEarth
Notably, this planet appears to receive about as much sunlight as Mars does.
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Honestly, I like the idea that we have a LHS 1140 b here in 55 Cancri B c, though I wouldn't get my hopes too high up; certainly it could also be a neptunian, although I think I wouldn't expect a bare rock here.
In Orion's Arm, the star B is named Rheticus, orbited by three planets: Metius, Huygens, and Bayer. The naming theme follows that of Copernicus system. This naming theme will be kept, although I might attempt to find more fitting names.
More interestingly, this work also checked RV data of the secondary star in this system (B), and found two planets: 55 Cancri B b and B c, superterran/subneptunian worlds with the following parameters:
55 Cancri B b
- Semi-major axis: 0.044 au
- Orbital period: 6.7994 days
- Mass: 3.5 ± 0.8 MEarth
55 Cancri B c
- Semi-major axis: 0.13 au
- Orbital period: 33.747 days
- Mass: 5.3 ± 1.4 MEarth
Notably, this planet appears to receive about as much sunlight as Mars does.
====
Honestly, I like the idea that we have a LHS 1140 b here in 55 Cancri B c, though I wouldn't get my hopes too high up; certainly it could also be a neptunian, although I think I wouldn't expect a bare rock here.
In Orion's Arm, the star B is named Rheticus, orbited by three planets: Metius, Huygens, and Bayer. The naming theme follows that of Copernicus system. This naming theme will be kept, although I might attempt to find more fitting names.