White Dwarf Planets Playing to Einstein's Theory on Gravitational Waves

Scientists using the radio signals from a pulsar neutron star binary system detected waves in the structure of space time indirectly. According to the report, the find, which demanded an accurate timing of the radio signals, got its discoverers a Nobel Prize. Presently a team of astronomers have detected the same effect at optical wavelengths, in light from a pair of eclipsing white dwarf stars.

It was last year that the pair of white dwarfs was detected in the system called SDSS J065133.338+284423.37 (J0651 for short). The distance between the pair is approximately one third of the earth moon distance due to which they complete orbit in less than 13 minutes.

"Every six minutes the stars in J0651 eclipse each other as seen from Earth, which makes for an unparalleled and accurate clock some 3,000 light-years away," said study lead author J.J. Hermes, a graduate student working with Professor Don Winget at The University of Texas at Austin.

The team was able to detect Einstein's theory of general activity in the system that states moving objects create subtle ripples in the fabric of space time known as gravitational waves. And these waves carry away energy causing the stars to come closer and orbit each other at faster rate.

 "Compared to April 2011, when we discovered this object, the eclipses now happen six seconds sooner than expected," said team member Mukremin Kilic of The University of Oklahoma.

"This is a general relativistic effect you could measure with a wrist watch," added SAO's Warren Brown.

According to the team the period will shrink every year due to which eclipses will happen more than 20 seconds sooner. The stars are expected to merge in two million years.

The study was carried out in The Astrophysical Journal Letters.