Why Aging Stars Suffer A Sudden Luminosity Dip

When low-mass stars like our Sun age, they leave the main sequence and follow the Red Giant Branch. As they ascend this branch, their luminosity steadily increases. But there's a sort of hiccup in the path called the RGB luminosity bump, where their luminosity suddenly dips. Astrophysicists have struggle to explain this, but one astrophysicist might have the answer.