Astronomers have made an exceptional discovery by figuring out a secret planetary system 21 light years from earth that includes three super-Earths and one giant planet. The planetary system named HD219134 in the constellation Cassiopeia has one outer giant planet and three inner super-Earths, one among which is known as HD219134b. It transits in front of a star and is by far the closest transiting planet.
The star on the other hand is a 5th magnitude K dwarf which is slightly colder and less massive than the sun. It is visible with naked eye all year round. The three planets in HD219134 has a configuration which is similar to our solar system i.e. they are mostly rocky. The discovery was made by HARPS-N telescope in Spain’s La Palma Island. Astronomers upon realising the presence of three planets sought help from NASA’s Spitzer space telescope that helped them determine the mass and density of HD219134b.
The mass density of HD219134b is 4.5 times than that of earth whereas its mean density is more or less similar to earth. The planet is 1.6 times larger than earth and thus the name super-Earth. Scientists are yet to ascertain details of other planets.