Scientists say they’ve discovered as many as seven planets orbiting a sun-like star.
It’s the richest planetary system discovered and may contain at least one planet nearly as small as Earth — which would make it the smallest planet found outside this solar system. One astronomer says it’s part of a growing body of evidence that the universe is full of planets — and that many could be similar to our own.
HD 10180, is located 127 light years away in the southern constellation of Hydrus. The five confirmed planets are large, about the size of Neptune — between 13 and 25 Earth masses —with orbital periods ranging from between six and 600 days. The planets’ distances from the star ranges from 0.06 and 1.4 times the Earth–Sun distance.
The first five were most comparable to Neptune.They are made essentially of rocks and ice. They have a solid core. But on top of that is a layer of gas, of hydrogen and helium.The sixth is possibly a Saturn-like planet, while the seventh, the smallest, would be so close to its star that its “year’’ would take just over a day.
Scientists used the observatory’s 11.8 foot telescope at La Silla, Chile, to study the planets’ parent star, known as HD 10180. Over six years, they took 190 measurements, checking the star for the telltale wobbling caused by the gravitational forces of nearby planets.