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God keeps his finger on the c constant slider (lemmy.world)
submitted 6 months ago by to c/science_memes@mander.xyz
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[–] 3 points 6 months ago (6 children)

Have there ever been any stars or planets, that we see in the night sky, just disappear? I always wondered if that has happened during the last 4,000 years or so of celestial observation. When I was a kid I was told that some stars are so far away that they were dead but the light we are receiving from them is still continuing to arrive as starlight. Have we seen that dead star light wink out? I know the universe is very old and the last 4,000 years was just a blink of an eye, but I'm curious if anyone knows if this has happened.

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  • [–] 7 points 6 months ago* (3 children)

    That's what supernova are.

    Other stars like our own will eventually, in about 5 billion years, become a red giant and then a white dwarf, but will take hundreds of billions of years to cool to the point where they no longer emit light, so none of them have had enough time for that to happen yet.

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  • [–] 1 point 6 months ago (2 children)

    I get the definition and extrapolation, but I was wondering if any observable phenomena has occurred. Thanks.

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  • [–] 3 points 6 months ago* (1 child)

    If you're asking whether any supernova have occurred, then yes, they have.

    If you're asking whether humans have seen a supernova, then yes also - the most famous is probably SN 1006, which was the brightest stellar object ever seen by humans, brighter than venus in the sky, and was recorded in the year 1006 by many different societies. There have been several others documented over the last 1000 years.

    In addition, which might be more what you're asking, there have been stars, or at least light sources that look like stars, which have simply appeared and vanished again within a matter of minutes or hours, and their disappearances are often left poorly explained - they could be supernova that for some reason didn't go nova, or something else entirely. There's a project called VASCO (Vanishing and Appearing Sources during a Century of Observation):

    https://www.iflscience.com/disappearing-stars-in-the-1950s-associated-with-uaps-and-nuclear-weapons-tests-

    https://www.smithsonianmag.com/air-space-magazine/stellar-mystery-how-could-100-stars-just-vanish-180973821/

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