In 2009, NASA sent Kepler Space Telescope in the space as an observatory to discover the planets outside our Solar System. Since then, the astronomers have discovered a vast collection of exotic extrasolar planets. Although the discovered planets are not exactly alike, they all fit under general classifications.
Here we discuss some of the newly discovered class of planets by the astronomers:
The planets that fall under the Super-Jupiters classification are generally much larger in size than the Jupiter planet. Some of the planets are 10 to 15 times more massive compared to Jupiter. These planets do not possess solid surfaces to walk on. They are basically composed of hydrogen and/or helium.
The size of the Hot-Jupiter exoplanets is almost the same as of Jupiter. They are just a bit larger than Jupiter. This series of the exoplanets does not reside within the middle of their respective planetary systems. Rather, they orbit their parent star at an unusually close distance. Sometimes the distance is only of a fraction just like the Mercury orbits the Sun. The Hot-Jupiters are blisteringly hot. Moreover, these planets lack any solid surface.
The planets of the mini-Neptunes are much larger than our Earth. However, they are not quite large enough to match the Neptune or Uranus in size. In fact, the mini-Neptunes are transitional planets between the rocky bodies. This means that they are basically made up of gas. But they also contain considerably massive rocky cores which are present very far inward.
The pulsar planets orbit the stars which have already undergone the transition from the main-sequence mode to the final stage of the stellar evolution. Unlike other planets, they orbit a pulsar or a neutron star instead of orbiting a white-dwarf or a stellar-mass black hole. Although both the pulsar star and the stellar-mass black hole are merely a few kilometers across. The neutron star of the pulsar planets rotates at an extremely high speed. If one of the poles of the neutron is aligned toward the Earth during the rotation, it spits out a light. This happens because as the neutron rotates, it creates an illusion of pulsation.
Free-floating planets are also known as rogue or orphan planets. They wander interstellar space without being tethered to a parent star due to gravitation. The free-floating planets do not possess a specific size like other types of planets. However, most of them are generally large in size and orbited close in. The astronomers believe that these planets might be kicked out of their planetary system due to a gravitational perturbation with another planet.
The Super-Earth exoplanets have about 5 to 10 times more mass than that of Earth. However, they tend to have radiuses varying wildly in size depending on their composition.