Researchers at Penn State have announced they have discovered a new type of pulsating star with a brightness that oscillates periodically but only over one of its hemispheres. Pulsating stars typically have brightness that oscillates periodically across its entire surface.
https://www.slashgear.com/scientists-discover-a-pulsating-star-that-only-gets-brighter-in-one-hemisphere-10612694/
https://www.slashgear.com/scientists-discover-a-pulsating-star-that-only-gets-brighter-in-one-hemisphere-10612694/