white dwarfwhite dwarf
nounpl. white dwarfs
a planet-sized, very dense, collapsed star, the fuel of which has been exhausted: initially very bright and hot, it gradually evolves into a black dwarf
The collapsed remnant core of a low-mass star that has ejected its outer layers and can no longer sustain nuclear fusion. White dwarf stars are extremely dense, having no empty space between atoms, but lack the mass to reach the even more extremely dense states of a neutron star or black hole.
white dwarf (spot in center) enveloped by planetary nebula NGC 2440
(plural white dwarfs)