First a red giant cooks its planets, then it turns them into mini-stars

A long standing astronomical mystery may finally be solved. It involves dying stars, torched planets, rejuvenating those planets as kinda-sorta stars, and big ol' clouds of dust.

A lot of stars are what we call variable, meaning they change their brightness over time. Some are irregular, in that they just seem to get brighter and dimmer at random times (see Boyajian's Star), while others are regular or periodic variables, which get brighter and/or dimmer on regular cycles.

Almost all the reaso...