Super Earth Planet Discovered Second Smallest

The planet hunters to search for planets the size of Earth was never vanished. One by one the secrets surrounding objects Stars began to lift. This time, the planet hunters managed to detect extrasolar planets whose mass is only 4 times the mass of Earth.

Small isn't it? The planet is the second smallest planet found after the discovery of COROT 7b. This new planet discovery not only adds to the long list of super-Earth planet, but he also became another candidate who gives evidence that the era of small planets is no longer a foreign thing. It also can give the view that the existence of planet Earth-sized planets around stars is a common thing in a planetary system. 
Exoplanet HD 156668b with the name it only takes 4 days to orbit its parent star is 80 light years from Earth, precisely in the direction of the constellation of Hercules. The inventor of this planet, Andrew Howard of the University of California at Berkeley (UCB) and a team of California Planet Search (CPS) consisting of Geoff Marcy (UCB), Debra Fischer (Yale University), John Johnson (California of Institute of Technology) and Jason Wright (Penn State University), managed to make observations of this small planet using the Keck I telescope on Mauna Kea 10meter, Hawai'i.
Method Radial velocity Planet HD 156668b was found by using the radial velocity method or methods Wobble observed and captured by the instruments mounted Hires in the Keck telescope.
Radial velocity technique is most productive method of finding Exoplanet. At least nearly 400 Exoplanet found with this method, although most are Jupiter-sized planets.
With the radial velocity technique, we can determine the change in the radial velocity of stars and planets move around the center of mass. Planet's gravitational forces will disrupt the movement of stars, so that looks like a rock star. As they moved toward the center of mass, velocity star will be slightly changed, and seemed to move away from medekati and observers. The bigger the planet and the closer the planet to its parent star, then the sooner the star's movement and the greater the shift in the spectrum.
Shift the color spectrum are also likely to provide information and characteristics of the planet's mass to the astronomers. Information and Instructions pieces Can not deny, low-mass planets is one of the important goals in the search for extrasolar planets. Not only to meet the human dream to find planets similar to Earth in size and outside our Solar System, but also to complete the pieces of information that have been found.
The discovery of extrasolar planets in 1995 gave a new color as well mengumpulkn pieces of information from any planets found and from the system. From all that, the information found most frequently derived from mass planets into categories of large gas giant planets.
From the information available, astronomers will already have instructions from the formation and evolution of high-mass planets. But to understand the whole system, required pieces of information from mass planets like the planet's super-low-Earth. This information will provide instructions on how super-Earth planets formed and migrated. Are also likely to be a major goal of the program Eta-Earth Survey for Low Mass Planets led by Geoff Marcy.
Until now, the program has discovered two planets that have masses similar to Earth's mass. In the future will more and more clues that could be collected, because the era of super-Earth discovery plaet has begun.