Kepler-78b

Kepler - 78b (formerly KIC 8435766 b ) is an exoplanet discovered in 2013 about 400 light years away from the Earth. It orbits the Sun-like star, of spectral type G in the constellation Cygnus ( Swan), Kepler -78 at a distance of less than 1.6 million kilometers. Its origin is unclear due to the close proximity to its sun. Its orbit is not in the habitable zone.

Discovery

The planet was discovered with the help of the now no longer active space telescope Kepler. This telescope captures variations in brightness that occur when a planet seen from Earth just passes in front of its host star (transit ). The planet was first observed in 2013 in the framework of an eight- day observation. In addition to the brightness fluctuations contributed reflections incident light at its discovery. His discovery was first released on 30 October 2013.

Properties

The circling of Kepler- 78b star belongs to the spectral class G. For a circulation of extrasolar planet takes about 8.5 hours. The distance of Kepler- 78b to its sun is only one- hundredth of the distance between Earth and the Sun. Due to this close proximity to its sun, the temperature is estimated to be 2200 to 2800 ° C. Thus, the orbit is not in the habitable zone. Francesco Pepe, an astronomer involved in the discovery of the University of Geneva, Switzerland, referred to the planet as Earth-sized lava world " .. it can be imagined like a lava planet rather than on Earth -like planet".

The mass of Kepler- 78b is about 186 % that of the Earth, however, while it is only 16 % larger. The density roughly corresponds with the Earth. From this it is concluded that he is made ​​mostly of rock and iron. Between 20 and 60 % of the incident light is reflected.

He belongs to a newly discovered class of Earth-sized planets orbit the star in her less than 12 hours and is the first planet from this group, whose mass could be determined now. Its origin is still unclear. For one, he could not have come in such close proximity to Kepler, because the sun was at the time of their creation is greater and the current position would then located in it. On the other hand, it is not possible that it is subsequently migrated to this position because he would have fallen in this case in the sun. It is believed that Kepler - 78b will go down in the next 3 billion years ago, as the gravity of the sun is to wear it on and it will break eventually.