The same star is orbited by a giant planet

Jul 31, 2015 09:12 GMT  ·  By

A new study in the journal Astronomy & Astrophysics and authored by scientists at the University of Geneva and their colleagues at NCCR PlanetS announces the discovery of a previously undocumented planetary system lurking in the constellation of Cassiopeia at a distance of merely 21 light-years from our cosmic neighborhood. 

The newly discovered planetary system orbits a star called HD219134, which astronomers describe as ever so slightly colder and smaller than our Sun but nonetheless bright enough to be visible to the naked eye during nighttime.

There are three super-Earths in this system

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.

Of these planets, the closest to the star has an orbit of just 3 days. Astronomers estimate that it is about 1.6 times larger and 4.5 times more massive than Earth. Judging by its density, it might be that it also has a composition similar to that of our planet.

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. One of them weighs 2.7 times more than Earth. The other is quite heavier, its mass being 8.7 times greater than that of Earth.

There is also a giant planet, astronomers say

Apart from these super-Earths, the newly found planetary system documented around HD219134 holds a giant planet that scientists say resembles Saturn and that takes 3 years to orbit its parent star.

What with the rocky planets positioned quite close to the star and the giant considerably farther away, astronomers say this arrangement of orbs kind of reminds them of our Solar System. Hence, it's safe to assume it will be studied in further detail in the years to come.

“This system, reminiscent of our own Solar System with the inner ‘small’ planets and the outer gaseous one, will without doubt encounter a growing interest from the astronomical community,” the University of Geneva scientists behind this find said in a statement.