A typical white dwarf has a helium and hydrogen outer layer covering a core of carbon and oxygen produced from burning helium. Now, S O Kepler of the Universidade Federal do Rio Grande do Sul in Porto Alegre, Brazil, and colleagues have found a white dwarf with an almost pure oxygen outer layer. The next most abundant elements are neon and magnesium at concentrations that are 25 or more times smaller. Remarkably, no hydrogen or helium are detected. Its mass is also the average mass for a neutron star, making it hard to think of it as coming from carbon burning, which should make it heavier. The discovery challenges conventional thinking and opens the door to a much better understanding of both white dwarfs and stellar evolution.