• Boddhisatva@lemmy.world
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      21 hours ago

      You’re not wrong. Everything orbits the center of mass of the system, meaning the mass of the star and the body in orbit. And that is handy for astronomers, many exoplanets have been found using the Doppler spectroscopy method. Doppler spectroscopy measures the Doppler shift in the star’s light as it is pulled towards and away from us by planets in orbit. The newest spectrographs are sensitive enough to detect a star’s wobble caused by an Earth sized body in orbit. The barycenter is still within the star, but not at the center of the star’s mass.

    • pixeltree@lemmy.blahaj.zone
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      1 day ago

      For most bodies the barycenter, while not the same as the center of mass, is still inside the sun. This one isn’t, making it notable

    • fedditter@feddit.org
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      1 day ago

      Fun fact: You actually pull the Earth up with the same force it pulls you down… Newton’s Third Law.

    • JackbyDev@programming.dev
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      1 day ago

      No, this is actually really relevant. This is part of the logic applied to labeling Pluto a dwarf planet. Pluto and it’s moon do this, Earth and our moon do not. Yes, obviously the center of mass of the two isn’t the exact center of the earth but it’s still within the earth.

      • deltapi@lemmy.world
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        13 hours ago

        And Pluto knows that Pluto’s
        Hot shit
        And you know Pluto knows it
        “I won’t ever be a planet
        It don’t matter 'cause I know that I’m still”
        Hot shit
        “And you’re hot shit too, so get out of your brain And just do what you’re supposed to do”

      • captainlezbian@lemmy.world
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        1 day ago

        Asking a physicist about the center of an object is like asking a Tumblr user about thr color of the sky. The only response will be “which one?” And a sigh of exhaustion

        Center of volume ≠ center of mass ≠ center of systemic gravity ≠ center of lift…

        • MajorasTerribleFate@lemmy.zip
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          8 hours ago

          Not to mention “an object” is just a construct describing a collection of molecules that themselves don’t necessarily sit still or all stick around.

      • WraithGear@lemmy.world
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        1 day ago

        but the density of an object is variable. i mean you can define the diffrence between an orbit and a co-spiral to be based on the physical size of the denser planetary body containing the orbit center point, though that seems arbitrary.