HONOLULU -- The W.M. Keck Observatory on Mauna Kea helped astronomers identify the smallest two-star (binary) system so far, officials said.

The discovery appears in the March 10 edition of the Astrophysical Journal Letters.

The system HM Cancri was discovered in 1999 by a German satellite telescope. For the past few years, a group of international scientists has been trying prove a theory that HM Cancri was a binary system.

A team led by Gijs Roelofs of the Harvard-Smithsonian Center of Astrophysics used the 10-meter Keck I telescope to observe the stars as they orbited each other. They determined that the two "dead" stars revolve around each other every 5.4 minutes. That is the shortest orbit known to scientists.

"When the first data from the Keck telescope arrived, and our quick analysis showed the periodic shift of the spectral lines, we knew that we had succeeded. More than 10 years after its discovery, we finally had deciphered the nature of HM Cancri," said Arne Rau of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany.

The system is about 16,000 light years from Earth, officials said.

Astronomers said the finding will help them determine how two "normal" stars could shrink and spiral together.