A new set of star velocity data indicates that Gliese 710 has an 86 percent chance of ploughing into the Solar System within the next 1.5 million years.
The Solar System is surrounded by thousands stars, but until recently it wasn't at all clear where they were all heading.
In 1997, however, astronomers published the Hipparcos Catalogue giving detailed position and velocity measurements of some 100,000 stars in our neighbourhood, all gathered by the European Space Agency's Hipparcos spacecraft. It's fair to say that the Hipparcos data has revolutionised our understanding of the 'hood.
In particular, this data allowed astronomers to work out which stars we'd been closer to in the past and which we will meet in the future. It turns out that 156 stars fall into this category and that the Sun has a close encounter with another star (meaning an approach within 1 parsec) every 2 million years of so.
In 2007, however, the Hipparcos data was revised and other measurements of star velocities have since become available. How do these numbers change the figures?
Today, Vadim Bobylev at the Pulkovo Astronomical Observatory in St-Petersburg gives us the answer. He's combined the Hipparcos data with several new databases and found an additional nine stars that have either had a close encounter with the Sun or are going to.
But he's also made a spectacular prediction. The original Hipparcos data showed that an orange dwarf star called Gliese 710 is heading our way and will arrive sometime within the next 1.5 million years.
Can We Haz Comets?!
hat tip to James.