Astronomers initially thought they'd discovered a planet orbiting 40 Eridani A using radial velocity, but it was later found to be an optical illusion from starspots.
The star's surface patches, with varying temperatures, create the illusion of the star wobbling as they move in and out of view due to rotation, similar to a flipbook animation.
Planets and stars orbit a shared center of gravity, usually located much closer to the star due to its higher mass, making the star appear to wobble around it.
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