| Mu Arae d / Rocinante | |
| Discoverer: | Goździewski et al. Mayor, Pepe |
| Discovery Site: | Chile South America |
| Discovered: | August 5, 2006 |
| Discovery Method: | Doppler Spectroscopy |
| Apsis: | astron |
| Aphelion: | 0.9823AU |
| Perihelion: | 0.8597AU |
| Semimajor: | 0.921AU[1] |
| Eccentricity: | 0.0666 ± 0.0122 |
| Period: | 310.55 ± 0.83 d 0.8502 y |
| Time Periastron: | 2452708.7 ± 8.3 |
| Arg Peri: | 189.6 ± 9.4 |
| Semi-Amplitude: | 14.91 ± 0.59 |
Mu Arae d, also known as HD 160691 d, formally named Rocinante, is an extrasolar planet orbiting the star Mu Arae of the constellation Ara.
The planet has a mass about half that of Jupiter and orbits at a distance of 0.921 AU from the star with a period of 310.55 days. The planet may be located at a distance close enough to the star to receive a comparable amount of ultraviolet radiation as the Earth does from the Sun. However, it is too close to the star to be able to support liquid water at its surface.[2] Furthermore, given its mass, the planet is likely to be a gas giant with no solid surface.
In July 2014 the International Astronomical Union launched NameExoWorlds, a process for giving proper names to certain exoplanets and their host stars.[3] The process involved public nomination and voting for the new names.[4] In December 2015, the IAU announced the winning name was Rocinante for this planet.[5] The winning name was submitted by the Planetario de Pamplona, Spain. Rocinante was the horse of the lead character of the novel Don Quixote.[6]