Pulsar punches hole in companion star disc

Observations by Chandra are providing NASA with new insight into the power of pulsars.

These images contain X-ray evidence from Chandra that a clump of stellar material has been jettisoned away from a double star system at incredibly high speeds. Researchers think that the pulsar knocked out the chunk of debris, which spans over a hundred times the size of the Solar System, when it collided with the disk around the massive star while traveling in its elliptical orbit. This trio of images shows Chandra observations taken between December 2011 and February 2014. The bright source in the center of these images is the binary system, while the smaller point-like source to the lower right seen in the second two observations is the clump that has been dislodged.

Below this artist’s illustration are three images captured by Chandra showing evidence that a clump of material has been blasted out of a double star system at high speeds. X-ray: NASA/CXC/PSU/G.Pavlov et al; Illustration: NASA/CXC/M.Weiss

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NASA’s Chandra X-ray Observatory is tracking a clump of gas hurtling through space at four million miles an hour that was formed when a pulsar punched a hole in the disc around its companion star.

Double star system PSR B1259-63/LS 2883 consists of a massive star 30 times as big as the Sun and a pulsar, an ultra-dense neutron star left behind by a supernova explosion.

The pulsar’s huge companion star is rotating close to break-up speed, creating a disc of material around it.

The pulsar then passes through this disc every 41 months as it makes its closest approach to the star.

The pulsar is spinning 20 times a second and emits regular pulses as it does so, moving in an elliptical orbit around its companion star.

This rapid rotation combined with the pulsar’s magnetic field has created a blast of high-energy particles, which is flying into space at almost the speed of light.

“These two objects are in an unusual cosmic arrangement and have given us a chance to witness something special,” says George Pavlov of Penn State University in State College, Pennsylvania, lead author of a paper analysing the results.

“As the pulsar moved through the disc, it appears that it punched a clump of material out and flung it away into space.

”The clump being observed by Chandra is 100 times the size of the Solar System, but only has the mass equivalent to all the water in Earth’s oceans.

“After this clump of stellar material was knocked out, the pulsar’s wind appears to have accelerated it, almost as if it had a rocket attached,” explains co-author Oleg Kargaltsev of George Washington University (GWU) in Washington, DC.B1259 is located about 7,500 light years from Earth and Chandra has already observed the system three times between December 2011 and February 2014.

The clump is moving at an average speed of about 7% of the speed of light, accelerating to 15% the speed of light between the second and third observations.

“This just shows how powerful the wind blasting off a pulsar can be,” says co-author Jeremy Hare, also of GWU.

“The pulsar’s wind is so strong that it could ultimately eviscerate the entire disc around its companion star over time.

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”Chandra is to continue its observations of B1259 and its moving clump later this year and in 2016.