Most Extreme White Dwarf Binary System Found With Orbit Of Just Five Minutes

Graphic of HM Cancri. (Credit: Image courtesy of University of Warwick)

From Science Daily:

Science Daily (Mar. 9, 2010) — An international team of astronomers has shown that the two stars in the binary HM Cancri definitely revolve around each other in a mere 5.4 minutes. This makes HM Cancri the binary star with by far the shortest known orbital period. It is also the smallest known binary. The binary system is no larger than 8 times the diameter of the Earth which is the equivalent of no more than a quarter of the distance from the Earth to the Moon.

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