Three super-Earths found 21 light years from Earth

The star lies just off the The four-planet system had been hiding out in the M-shaped, northern hemisphere constellation Cassiopeia, “just” 21 light years from Earth, a team reported in the journal Astronomy & Astrophysics.

Named HD219134, like the star it orbits, this planetary system located in the constellation of Cassiopeia includes three super-Earths, i.e. planets whose mass is bigger than that of our planet but smaller than that of giants such as Uranus and Neptune. However, it is the closest transiting planet discovered by scientists thus far, giving them the opportunity to further study its atmosphere and composition, the authors told the website.

The planetary system resembles our own to a high degree, the astronomers said. The idea was to check for a potential transit of the planet in front of the star, a mini eclipse, that would allow us to measure the size of the planet. That planet which was called HD 219134b is almost 5 times heavier than the Earth and more than 1.5 times larger. Its mean density is close to the density of the Earth, suggesting a possibly similar composition as well.

As for the other rocky world discovered in this system, scientists say they have an orbit of 6.8 days and 46.8 days, respectively. If, by chance, these 2 planets would be in a coplanar configuration with their 3rd inner sister, as often observed for compact systems, the whole family might be transiting. The group hopes to capture other transits in the near future.

The lately found solution has at its core a pygmy stars professionally titled Human resource 8832 that’s brilliant a sufficient amount to be seen having the bare off but lighting control and less space-consuming than our sunshine.

Michael Gillon of the University of Liege in Belgium, the study’s co-author, sends his gratitude to NASA’s Kepler mission because it opened the knowledge that super-Earths are ever-present in our galaxy but still much is to know about them. In the outer region of the planetary system, the astronomers identified a giant planet, similar to Saturn. “In particular, the future CHEOPS satellite of the European Space Agency (ESA), developed under Swiss leadership with a strong involvement of UNIGE and of the University of Bern, will provide the ideal tool for such observations”, comments with enthusiasm Prof. “Indeed, the proximity and brightness of the star makes the system the most favourable one for an in-depth characterisation of the planet physical properties”, said the astronomers.