Exoplanets - as many of seven of them - spotted in newfound star system
There is another -like out there with an intriguing family of orbiting about and it could be the closest parallel to our own that astronomers have found yet. European astronomers discovered a planetary system containing at least five planets, orbiting the star HD 10180, with evidence that two other planets may be present. If confirmed, one of those would have the lowest mass ever found.
鈥淲e have found what is most likely the system with the most planets yet discovered,鈥� says Christophe Lovis, who led the team. 鈥淭his remarkable discovery also highlights the fact that we are now entering a new era in research: the study of complex planetary systems and not just of individual planets. Studies of planetary motions in the new system reveal complex gravitational interactions between and give us insights into the long-term evolution of the system.鈥�
To make this system even more intriguing, the team also found evidence that the distances of the planets from their star follow a regular pattern, as also seen in . 鈥淭his could be a signature of the formation process of these planetary systems,鈥� said team member Michel Mayor.
HD 10180, is located 127 away in the southern of . The five confirmed planets are large, about the 鈥� between 13 and 25 masses 鈥攚ith orbital periods ranging from between six and 600 days. The planets鈥� distances from the star ranges from 0.06 and 1.4 times the Earth鈥�.
鈥淲e also have good reasons to believe that two other planets are present,鈥� said Lovis. One would be a -like (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. It is very close to its host star, at just 2 percent of the Earth鈥揝un distance. One 鈥測ear鈥� on this planet would last only 1.18 Earth-days.
鈥淭his object causes a wobble of its star of only about 3 km/hour鈥� slower than walking speed 鈥� and this motion is very hard to measure,鈥� says team member Damien S茅gransan. If confirmed, this object would be another example of a hot , similar to -7b.
The team used the planet-finding HARPS spectrograph, attached to ESO鈥檚 3.6-metre at La Silla, Chile, and made observations of HD 10180 for six years.
The newly discovered system of planets around HD 10180 is unique in several respects. First of all, with at least five -like planets lying within a distance equivalent to the of , this system is more populated than our System in its inner region, and has many more massive planets there. Furthermore, the system probably has no -like . In addition, seem to have almost circular .
With this new announcement, the total number of exoplanets found is 472.
The team鈥檚 paper was submitted to and (
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