"Chandra data (above, graph) from observations of RX J0806.3+1527 (or
J0806), show that its X-ray intensity varies with a period of 321.5
seconds. This implies that J0806 is a binary star system where two
white dwarf stars are orbiting each other (above, illustration)
approximately every 5 minutes.

The short orbital period implies that the stars are only about 50,000
miles apart, a fifth of the distance from the Earth to the Moon, and
are moving in excess of a million miles per hour. According to
Einstein's General Theory of Relativity, such a system should produce
gravitational waves -ripples in space-time - that carry energy away
from the system at the speed of light.

Energy loss by gravitational waves will cause the stars to move closer
together. X-ray and optical observations indicate that the orbital
period of this system is decreasing by 1.2 milliseconds every year,
which means that the stars are moving closer together at a rate of
about 2 feet per day."

http://chandra.harvard.edu/photo/2005/j0806/

http://i.ytimg.com/vi/ryqN6dyUmJg/0.jpg

"With its extremely short orbital period, RX J0806.3+1527 is also a
prime candidate for the detection of the elusive gravitational waves ,
predicted by Einstein's General Theory of Relativity. They have never
been measured directly, but their existence has been revealed
indirectly in binary neutron star systems.

A planned gravitational wave space experiment, the European Space
Agency's Laser Interferometer Space Antenna (LISA) that will be
launched in about 10 years' time, will be sufficiently sensitive to be
able to reveal this radiation from RX J0806.3+1527 with a high degree
of confidence. Such an observational feat would open an entirely new
window on the universe."

http://www.eso.org/public/news/eso0211/

Double-A