The pulsar is twice as heavy as the sun, only 25 km (15.5 m) across

Apr 29, 2013 16:01 GMT  ·  By
The gravity waves created by the two objects are quite peculiar (the pulsar is not drawn to size)
   The gravity waves created by the two objects are quite peculiar (the pulsar is not drawn to size)

Einstein's Theory of General Relativity is almost a century old and, while it doesn't explain everything we've observed in nature, it's still the best thing we've got to explain gravity and its effects and not for lack of trying.

The fact remains, gravity is peculiar enough that studying it or coming up with more comprehensive theories has proven very difficult.

According to Einstein, gravity bends the very fabric of space, but its effect is minute even for the largest of objects.

To study the effects gravity has on space itself, you need a very heavy object or very precise measurements. Luckily, The European Southern Observatory has managed to find one of the former.

Astronomers using ESO's cleverly named Very Large Telescope have found a very large (weight wise) neutron star, the largest to date, with a companion star orbiting very close.

Neutron stars are massively packed objects, there's so much matter compacted into such a tiny space that it breaks down to its components, neutrons in particular, hence the name.

This particular neutron star, PSR J0348+0432, is twice as heavy as the sun, but only 20 kilometers, 15.5 miles, in diameter. It spins 25 times per second. It's also a pulsar, it emits a beam of electromagnetic radiation from its poles.

It's the heaviest neutron star ever discovered, but that's not the only thing that's peculiar about it. It also has a companion star, a much lighter white dwarf which circles it every two and half hours.

Because the companion star is so close to the neutron star, the effects of gravitational waves are (relatively) easily detectable. The two stars' combined gravity fields create strange ripples in the space around them and the two lose energy relatively fast through the gravity waves they emit.

The loss of kinetic energy is translated directly in a slowdown of the orbiting speed. The theory predicts a slowdown of eight million of a second in a year.

This has been confirmed in practice as it's exactly what the combined efforts of ESO's Very Large Telescope, which observed the companion star, and radio telescopes which observed the pulsar, discovered.

This is the most precise measurement of the effects of gravity waves on objects to date and the peculiar duo will be of great interest to scientists looking to study the extreme effects of gravity.