Printer friendly version
Astronomer finds evidence for record-breaking nine planet system
12 April 2012
Hertfordshire, University of
A study by Mikko Tuomi, an astronomer at the University of Hertfordshire, has revealed that the planetary system around the star named HD 10180 may have more planets in its orbits than our own Solar system. Dr Tuomi carried out his analysis as part of the EU research network RoPACS, being led in Hertfordshire.
Originally reported to be orbited by seven planets in 2010, re-analysed data from the HARPS (High Accuracy Radial Velocity Planet Searcher) now indicates that the star has nine planets. This discovery is significant as most planetary systems discovered so far have far fewer planets. Located 130 light years away, the star is not within reach of foreseeable human space travel, but in astronomical distances, it is still considered to be in the Solar neighbourhood.
The study, accepted for publication in the journal Astronomy and Astrophysics, verifies the existence of the previously announced seven planets and shows that there are likely to be two additional planets orbiting the star. The two newly detected signals are probably those of planets classified as hot super-Earths with orbital periods around the star of 10 and 68 days.
These new planets are closer to the star’s surface than the Earth is to the Sun which makes them too hot to be able to maintain water on their surfaces in its liquid form. They have masses of 1.9 and 5.1 times that of our planet Earth which suggests that they are solid rocky bodies and make them among the smallest planets outside of our Solar system detected to date.
Future observations are required to verify the existence of these planet candidates and to establish the HD 10180 star system as the richest planetary system known to humankind - certainly a star worth keeping our telescopes on into the future.
An artist’s conception of the planetary system around HD 10180. One of the new Super-Earth planets HD 10180j is seen in the foreground (on the left hand side of the picture), with the nearby Neptune-like planet HD 10180e in the background (on the right-hand side of picture with blue cloudy atmosphere). The central star and the other 7 planets can be seen in the distance, including the second new Super-Earth HD 10180i, third out from the central star.