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A Star Grazed Our Solar System 70,000 Years Ago, Early Humans Likely Saw It (space.com)

Posted by BeauHD on from the blast-from-the-past dept.

schwit1 shares a report from Space.com: Some distant objects in our solar system bear the gravitational imprint of a small star's close flyby 70,000 years ago, when modern humans were already walking the Earth, a new study suggests. In 2015, a team of researchers announced that a red dwarf called Scholzs star apparently grazed the solar system 70,000 years ago, coming closer than 1 light-year to the sun. For perspective, the suns nearest stellar neighbor these days, Proxima Centauri, lies about 4.2 light-years away. The astronomers came to this conclusion by measuring the motion and velocity of Scholzs star -- which zooms through space with a smaller companion, a brown dwarf or "failed star" -- and extrapolating backward in time. Scholz's star passed by the solar system at a time when early humans and Neanderthals shared the Earth. The star likely appeared as a faint reddish light to anyone looking up at the time, researchers with the new study said. The study has been published in the journal Monthly Notices of the Royal Astronomical Society: Letters.

7 of 164 comments (clear)

  1. Grazed? by Viol8 · · Score: 4, Informative

    One light year is still WAY beyond the bounds of our known solar system and lets nor forget that the oort cloud is still pretty theoretical and no one has actually seen one of these objects yet in situ (though the claim is this is where comets come from) unlike those in the kuiper belt. So saying it grazed out solar system is pushing it a bit. If it had strayed into the kuiper belt yes , otherwise, umm, not really.

    1. Re: Grazed? by Anonymous Coward · · Score: 5, Informative

      Read the first link in the summary, or even just the first sentence in the quote.

      This isn't just some theoretical perturbation. We have quite the catalog of objects with hyperbolic orbits, and their points of origin is rather clumpy instead of randomly spread out across the soy or even a plane. The clumps suggest specific events that caused changes in distant orbits.

      We've known this star got close in the past for some time, the news is that someone showed that there is a category of these objects that matches the effects expected from the location and timing of the star, basically connecting the dots with some work.

      That is the exact opposite of your claim that this only affects hypothetical objects not observed, which should have been obvious if you did read and comprehend the summary.

  2. The star was not visible to naked-eye observers. by Ihlosi · · Score: 4, Informative

    Magnitude ~11, that's really dim.

  3. Re:Modern humans by GrumpySteen · · Score: 4, Informative

    It means they're talking about Homo sapiens (same species as all the idiots wandering around on the planet today) who were around 70,000 years ago along side Homo neanderthalensis (who were not modern humans and are no longer around, unless you count some DNA left over from our ancestors fucking anything that held still long enough).

    https://en.wikipedia.org/wiki/...

  4. Incorrect reporting by Stoutlimb · · Score: 4, Informative

    Whoever authored the science news did not check their facts. Scholz's Star had an estimated absolute magnitude of 11.4 at closest approach, which is nowhere near visible enough to be seen with the naked eye. Unless telescopes were in use 70,000 years ago, it's clear that nobody would have had any clue what was going on.

  5. Re:The star was not visible to naked-eye observers by Anonymous Coward · · Score: 2, Informative

    Scholz's star is currently 18.3 magnitude, and these flares are supposed to subtract 9 magnitudes.

    This should be visible by the The All Sky Automated Survey which monitors everything brighter than 14 magnitude.

    So we probably already have the data to answer the question of likelihood. It's surprising that the Scholz's star researchers aren't doing it.

  6. Re:Sigh. by breeze95 · · Score: 5, Informative

    1 light-year is 63,241 AU.

    An AU is the distance from the Earth to the Sun.

    The solar system is about 40AU (depending on your definition of planet).

    So "close" is really... well, testing things a bit. Astronomically, yes, very close.

    Practically? It's 20,000 times the size of the entire solar system away and to my knowledge only two objects have ever left the solar system.

    Chronologically? It happened 70,000 years ago which, again, is tiny in astronomical terms but it's already long gone. We could do nothing about it in a reasonable time, we'd barely be able to study it, and if it was slightly to the left we'd all be interstellar dust (again) by now.

    Though interesting, it's hardly close or anything we can really utilise or study,

    I'd be more worried along the lines of "chances are something else could come and go this and wipe us out and likely we'd never know it was going to happen". Not just stray asteriods (which obviously would be knocked for six by something like this straying close) but an entire damn star. That's solar-system-ending.

    The solar system is way bigger than 40 AU. The Oort cloud is part of the solar system and it extends to about 3 light years. So, the solar system extends, at least, to 3 light years. Not to mention, the sun's magnetic bubbles extend that far. I'm not sure why you stopped at the last planet and not include the Kuiper Belt and Oort Cloud as part of the solar system.