Keck telescope confirms smallest known star duo

Astronomers using the W. M. Keck Observatory have identified the smallest known binary system to date. The system, called HM Cancri, consists of two dead stars that revolve around each other in 5.4 minutes, by far the shortest known orbital period of any pair of stars. The team, led by Gijs Roelofs of the Harvard-Smithsonian Center of Astrophysics, used the 10-meter Keck I telescope with its Low Resolution Imaging Spectrograph to study the velocity changes in the spectral lines in the light of HM Cancri. They observed that as the stars orbited each other, the system’s spectral lines shifted…