SoylentNews

takyon writes:

Astrophysicists have predicted the existence of an exoplanet orbiting between two known exoplanets around the red dwarf Gliese 832 (it is a large red dwarf of about 0.45 solar masses at a distance of 16.1 light years from the Sun). The two currently known exoplanets are Gliese 832c with a mass of over 5.4 Earth masses at around 0.162 AU from the star, and Gliese 832b with over 0.64 Jupiter masses at around 3.4 AU away. Gliese 832c is in the habitable zone of the star, but may be hot with a Venus-like atmosphere.

The predicted planet could have a mass anywhere from 1 to 15 Earth masses, at a distance of 0.25 to 2 AU from the star:

For this research, the team analyzed the simulated data with an injected Earth-mass planet on this nearby planetary system hoping to find a stable orbital configuration for the planet that may be located in a vast space between the two known planets.

[...] "We also used the integrated data from the time evolution of orbital parameters to generate the synthetic radial velocity curves of the known and the Earth-like planets in the system," said Satyal, who earned his Ph.D. in Astrophysics from UTA in 2014. "We obtained several radial velocity curves for varying masses and distances indicating a possible new middle planet," the astrophysicist noted.

For instance, if the new planet is located around 1 AU from the star, it has an upper mass limit of 10 Earth masses and a generated radial velocity signal of 1.4 meters per second. A planet with about the mass of the Earth at the same location would have radial velocity signal of only 0.14 m/s, thus much smaller and hard to detect with the current technology.

"The existence of this possible planet is supported by long-term orbital stability of the system, orbital dynamics and the synthetic radial velocity signal analysis", Satyal said. "At the same time, a significantly large number of radial velocity observations, transit method studies, as well as direct imaging are still needed to confirm the presence of possible new planets in the Gliese 832 system."

Dynamics of a Probable Earth-mass Planet in the GJ 832 System (DOI: 10.3847/1538-4357/aa80e2) (DX)

Original Submission