KPD 0005+5106

KPD 0005+5106 is a helium-rich white dwarf star located 1300 light-years from Earth. As a "pre-white dwarf", the star is believed to still be in the helium-burning phase, just before nuclear fusion finally stops. It is the hottest known white dwarf, with a temperature of 200,000 K.

Possible companion object
The star KPD 0005+5106 has been observed to emit high-energy X-rays that regularly increase and descrease in luminosity every 4 hours and 42 minutes. This indicates that the star possibly has a companion orbiting it, either a low-mass star or a planet. The white dwarf pulls material from its companion into a disk around itself, before it slams into its north and south poles. The concentration of material at the poles causes the creation of two bright spots emitting high-energy X-rays.