Unveiling Three New Stars: Rare Hot Pre-White Dwarfs Discovered

Astronomers discovered three rare hydrogen-deficient pre-white dwarfs with helium-dominated atmospheres. These include an O(He) star likely formed from helium white dwarf mergers, a PG1159 star with the lowest known surface gravity in its class, and a CO-sdO star formed from disrupted white dwarf mergers. Their unique characteristics shed light on unconventional stellar evolution pathways.