by Matt Williams, Universe Today
It's known as HIP 85605, one of two stars that make up a binary in the Hercules constellation roughly 16 light years away. And if a recent research paper produced by Dr. Coryn Bailer-Jones of the Max Planck Institute for Astronomy in Heidelberg, Germany is correct, it is on a collision course with our Solar System.
Now for the good news: according to Bailer-Jones' calculations, the star will pass by our Solar System at a distance of 0.04 parsecs, which is equivalent to 8,000 times the distance between the Earth and the Sun (8,000 AUs). In addition, this passage will not affect Earth or any other planet's orbit around the Sun. And perhaps most importantly of all, none of it will be happening for another 240,000 to 470,000 years from now.
"Even though the galaxy contains very many stars," Bailor-Jones told Universe Today via email, "the spaces between them are huge. So even over the (long) life of our galaxy so far, the probability of any two stars have actually collided—as opposed to just coming close—is extremely small."
However, in astronomical terms, that still counts as a near-miss. In a universe that is 46 billion light years in any direction – and that's just the observable part of it – an event that is expected to take place just 50 light days away is considered to be pretty close. And in the context of space and time, a quarter of a million to half a million years is the very near future.
The real concern is the effect that the passage of HIP 85605 could have on the Oort Cloud – the massive cloud of icy planetesimals that surrounds the Solar System. Given that it's distance is between 20,000 and 50,000 AU from our Sun, HIP 85605 would actually move through the Oort cloud and cause serious disruption.
Many of these planetesimals could be blown off into space, but others could be sent hurtling towards Earth. Assuming humanity is still around at this point in time, this could present a bit of an inconvenience, even if it is spread over the course of a million years.
As it stands, such "close encounters" between stars are quite rare. Stellar collisions usually only occur within binaries, where white dwarfs or neutron stars are concerned. "The exception to this is physically bound binary stars in a tight orbit," said Bailor-Jones. "It can and does happen that one star expands during its evolution and will then interfere with the evolution of the other star. Neutron-neutron star pairs can even merge.
--more at Physics.org
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| Our Solar System is due for a near-collision with HIP 85605, a star 16 light-years away, in roughly 240,000 years. Credit: Dana Berry, SkyWorks Digital, Inc. |
Now for the good news: according to Bailer-Jones' calculations, the star will pass by our Solar System at a distance of 0.04 parsecs, which is equivalent to 8,000 times the distance between the Earth and the Sun (8,000 AUs). In addition, this passage will not affect Earth or any other planet's orbit around the Sun. And perhaps most importantly of all, none of it will be happening for another 240,000 to 470,000 years from now.
"Even though the galaxy contains very many stars," Bailor-Jones told Universe Today via email, "the spaces between them are huge. So even over the (long) life of our galaxy so far, the probability of any two stars have actually collided—as opposed to just coming close—is extremely small."
However, in astronomical terms, that still counts as a near-miss. In a universe that is 46 billion light years in any direction – and that's just the observable part of it – an event that is expected to take place just 50 light days away is considered to be pretty close. And in the context of space and time, a quarter of a million to half a million years is the very near future.
The real concern is the effect that the passage of HIP 85605 could have on the Oort Cloud – the massive cloud of icy planetesimals that surrounds the Solar System. Given that it's distance is between 20,000 and 50,000 AU from our Sun, HIP 85605 would actually move through the Oort cloud and cause serious disruption.
Many of these planetesimals could be blown off into space, but others could be sent hurtling towards Earth. Assuming humanity is still around at this point in time, this could present a bit of an inconvenience, even if it is spread over the course of a million years.
As it stands, such "close encounters" between stars are quite rare. Stellar collisions usually only occur within binaries, where white dwarfs or neutron stars are concerned. "The exception to this is physically bound binary stars in a tight orbit," said Bailor-Jones. "It can and does happen that one star expands during its evolution and will then interfere with the evolution of the other star. Neutron-neutron star pairs can even merge.
--more at Physics.org
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