The remnant of CK Vulpeculae, previously known as the oldest recorded nova. Shown here, CK Vulpeculae is surrounded by a dusty torus (yellow), cool molecular gas (red) and hot atomic gas (blue). This image was taken using APEX & SMA (dust and molecular emission at submillimeter wavelengths, Kamiński et al. 2015) and Gemini (optical atomic emission, Hajduk et al. 2007).
Cosmic detectives are investigating a case of mistaken stellar identity: An exploding star that was once thought to be the oldest recorded nova — a nuclear explosion on the surface of a dead star — was more likely caused by the merger of two stars.