Washington: Scientists have discovered a planetary system containing at least five planets, orbiting the Sun-like star HD 10180 using ESO’s world-leading HARPS instrument.
There’s evidence of two more planets in the same system, which would make it similar to our Solar System in terms of the number of planets.
“We have found what is most likely the system with the most planets yet discovered,” said Christophe Lovis as saying.
“Studies of planetary motions in the new system reveal complex gravitational interactions between the planets and give us insights into the long-term evolution of the system,” he added.
The five strongest signals correspond to planets with Neptune-like masses — between 13 and 25 Earth masses — which orbit the star with periods ranging from about 6 to 600 days. These planets are located between 0.06 and 1.4 times the Earth–Sun distance from their central star.
Amongst the other two planets that could exist, one would be a Saturn-like planet (with a minimum mass of 65 Earth masses) orbiting in 2200 days. The other would be the least massive exoplanet ever discovered, with a mass of about 1.4 times that of the Earth.
So far, astronomers know of fifteen systems with at least three planets. The last record-holder was 55 Cancri, which contains five planets, two of them being giant planets.
Another important result found by the astronomers is that there is a relationship between the mass of a planetary system and the mass and chemical content of its host star.
The discovery is announced today at the international colloquium “Detection and dynamics of transiting exoplanets”, at the Observatoire de Haute-Provence, France.