Exoplanets In Kepler-36 System Are 'Super Earth' And 'Mini Neptune'

Researchers are curious about the physical conditions and evolution processes of two exoplanets that orbit the Kepler-36 system, according to study at Princeton University. Kepler-36 is a sun-like star that is located 1,530 light years away from Earth. The inner exoplanet is Kepler-36b, which is also referred to as "super-Earth," since it is larger than the Earth, but smaller than Neptune. The outer exoplanet, Kepler-36c, is larger than Kepler-36b and it is referred to as a "mini-Neptune." Both of these exoplanets have close orbits, which are separated by 0.013 astronomical units (AU), about five times the distance between Earth and the moon.

The researchers of the study James Owen and Timothy Mortom used data from NASA's Kepler exoplanet-hunting spacecraft to help them in determining the initial physical conditions of the two alien worlds.  

"We calculate the evolution of each planet independently, including evaporation and bolometric irradiation by the central star," the researchers wrote in a statement. "As we evaluate this evolution on grids of initial physical conditions, we are able to use the inferred posterior distribution of the planets' present-day properties calculated from the transit timing variations to constrain these initial conditions."

The team found that Kepler-36b has a core that has been stripped evaporatively. The inner planet's core-mass is about 4.4 Earth masses, while Kepler-36c has a core mass that is about 7.3 times the mass of the Earth. The researchers believe that these two exoplanets may have had the same formation processes. They found that Kepler-36c had a long cooling process, which lasted for more than 30 million years during the early stages of the planet's life.

The two planets have very diverse densities even though they so are close to each other. The researchers believe that a process probably created this system after 6 billion years of evolution. The researchers anticipate that their findings could provide new insights on the evolution of exoplanets.

The findings of this study were published in ArXiv.

Related Articles

'Sleeping Giant': Elliptical Galaxy Has A Dark Secret

Hidden Galaxies Discovered Behind Milky Way

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).