A Solar System Like Home?

Afternoon Again Folks!

Here is the second of my “Space News” articles of the day.

Astronomers have identified a new planetary system (Planets orbiting a central Star). The discovery of a seventh planet around the Dwarf star KIC 11442793 could be a record, according to two separate teams of researchers. The system is quite similar to our Solar System, but all seven planets orbit much closer to their host star, which lies some 2,500 light-years from Earth.

One of the identifications was made by volunteers using the Planet Hunters website. The site was set up to allow volunteers to look at the public data from Nasa’s Kepler space telescope (The topic of one of my recent blogs!). Kepler uses the transit method to discover new planets (Which is the same method used by the SuperWASP project, of which my friends at Keele University are a part of!), which requires looking for the dip in light as an exoplanet passes in front of its host star. But there is simply too much data for Kepler’s scientists to examine every light curve, so they developed computer programmes to search for the signature of a planetary transit.

The new planet is the fifth furthest from its parent star, orbiting with a period of nearly 125 days. With a radius of 2.8 times that of the Earth, it fits into a family that now includes two roughly Earth sized worlds, three “Super-Earths” and two larger bodies.

“It actually looks like our Solar System in one sense, with all the small planets on the inside and the big planets on the outside. And that’s not necessarily what we always see,” said Robert Simpson from Oxford University. While there might be resemblances to our Solar System, all seven planets are closer to their host star. In fact they would all fit within the Earth’s distance from the Sun, making this a very crowded neighbourhood. “This is one of the reasons they are easy to see, because the closer they are to their sun, the more frequently they go around it,” said Dr Simpson.

Another star, HD 10180, has been claimed to have either seven, or nine planetary signals. A distant star called GJ 887C may also have a family of seven planets. We will have to wait and see if these become the new record breakers!