Astronomers have discovered a new secret planetary system located just 21 light years from earth. The planetary system, HD219134, contains three super-earths and one outer giant planet.

One of the three super-earths the planetary system contains orbits in front of a star and has a density equivalent to that of earth's. The astronomers who discovered the planetary system say the super-earth which transits in front of the star is the closest transiting planet known today.

Super-earths are actually those planets that have a mass higher than earth's but are lighter than gas giants like Neptune, Saturn or Jupiter.

NASA's Spitzer space telescope helped in deriving measurements of the planet with the shortest orbit, HD219134b. It has mass 4.5times higher than earth's and its size was 1.6 times larger.

"Its mean density is close to the density of earth, suggesting a possibly similar composition as well", said a statement from the University of Geneva, whose astronomers took part in the research.

Its distance from the star is very close and the temperature is about 700 degrees Kelvin, said study co-author Stephane Udry.

Researchers have to say the planet is not a good candidate to support life as its surface is melting. It won't be wrong to call it a melted lava world with volcanoes.

Due to its very close distance from the star, it does not have a habitable zone and highly unlikely to have key ingredient for life - water.

But nevertheless, the discovery offers an opportunity to further study composition of the closest transiting planet known to scientists.