Star to get within a trillion miles of Sun in 1.4 million years


Using the precise location and motion data obtained by the space telescope Gaia, astronomers have identified a star that 1.4 million years will come within a trillion miles of the Sun.

That distance puts it well within the outer parts of the theorized Oort cloud at the edge of the solar system. Since the star, Gliese 710, has a mass half that of the Sun, it will thus disturb many objects in that Oort Cloud, causing many to eventually fall sunward and produce a hail of comets several million years later. It will be, for a long time, the brightest object in the night sky, by far.

The data also identified a number of other stars that have in past or will in the future get close to the Sun. The most important result is not that these close approaches occur, but that they have found that they are relatively rare, and even the closest, Gliese 710, never really gets that close.

The universe is big, far bigger than we can really imagine.

9 comments

  • Col Beausabre

    Bob, My understanding is that complex systems get increasingly hard to predict the further out in time we go (the “clockwork universe” doesn’t exist – the universe is chaotic not deterministic) https://www.youtube.com/watch?v=T7rUb9ZgNIA so what stock can we place in a prediction that goes out 1,4 million years

  • Col Beausabre: You are generally correct, though these calculations are probably withing a range that is reasonably measurable. They are only outlining the most recent close approaches, both in the past and in the future. Considering the distances involved, 1.4 million years is actually not that long.

  • pzatchok

    If Gliese Does pass within our Oort Cloud area would that also place its (guessing here) theoretical Oort cloud into the gravitational realm of our outer planets?

    We could be looking at not our stuff getting tossed down the gravity well towards the Earth but its own stuff getting tossed in as well.

    There is an very very outside chance that we could steal a planet or moon from it also.

    Interstellar billiards.

  • David

    The linked article raises all sorts of interesting questions for further study. At what point does Gliese 710 replace Proxima Centauri as the closest star to Sol? And for how long? If, as the article implies, the Sol Oort cloud extends well out past 1 light year, what about Proxima’s? If Proxima has a similarly sized Oort cloud, they’ll be intermingling soon. I would assume Gliese probably lacks much of an Oort cloud if it’s been screaming around the stellar neighborhood at a tanget for who knows how long. And what’s the relationship of Sol, Proxima, and Gliese 710? Will Gliese get close enough to Proxima on the way in to pick up stuff to lob at us? Or, getting really fanciful thinking that far ahead, will it serve as a handy slingshot for far future interstellar missions?

  • LocalFluff

    This is not a runaway star but ordinary movements. The Sun makes full trip around the galaxy in about 220 million years (the dinosaurs lived 50,000 light years from here). The stellar neighborhood roughly follows that movement. The Sun also oscillates up and down in the 10,000 light years think galactic disk during its revolution, I don’t know how synchronized that movement is with other stars.

    The Oort cloud is traditionally defined to reach out to where the Sun’s gravity is dominated by the nearest stars. I would think that the many close encounters should’ve shrunk the Oort cloud over time, and perhaps given it an irregular shape. But comets entering the Solar System come equally from all directions, at least now when there’s no disturbance in any particular direction.

    The Oort clouds of stars having a close encounter should be shared and exchanged between the stars as the comets are taken over by the other star’s gravitational dominance. The orbital period of a comet 10,000 AU away is one million years, so an encounter would not affect the Oort cloud equally in all directions.

  • Captain Emeritus

    Dateline: 1,402,020 AD.

    Gliese 710 penetrates Oort Cloud!

    Women, children and minorities affected most!

  • pzatchok

    It was once theorized that we could use the resources of the Oort Cloud to hop and skip to the next solar system.

  • David K

    It could happen a lot sooner than that if people ever get their act together and build a Caplan Thruster in the Dyson Swarm that may exist in ten thousand years or so.

  • pzatchok

    My biggest fear for the human race is that we do not get out of our solar system fast enough.

    Fast enough as in before we run out of nuclear fuel. No other present technology will get us out there.

    We can build a generation ship now but we just do not have the energy to fuel it.

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