Pulsar Lands Knockout Blow on Star 30 Times Bigger Than the Sun

Images taken by the Chandra X-ray observatory telescope have revealed a cosmic collision between a dense neutron star, or pulsar, and a star 30 times bigger than our Sun.

The face-off between a pulsar and massive star 7,500 light years from Earth ended with the pulsar taking a chunk out of the latter, an analysis of images from the Chandra X-ray observatory has found.

According to the observations made using the telescope, which is designed to detect X-ray emissions from very hot regions of the Universe like exploded stars, clusters of galaxies, and matter around black holes, the pulsar was spinning 20 times per second when it took a clump of plasma out of its companion star, which is itself rotating at close to break-up speed.  

The scientists believe the X-ray emission picked up by Chandra was produced by the collision of the wind from the pulsar with the clump of matter ejected from the star, which is 30 times bigger than our sun, and spinning off a disk of material as it rotates. 

"This just shows how powerful the wind blasting off a pulsar can be," said co-author Jeremy Hare of George Washington University, whose study was published in the June 2015 issue of the Astrophysical Journal. 

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

The researchers calculated that although the chunk of material lost by the star is a hundred times the size of our Solar System, the mass lost by the star is equivalent to all the water in the Earth's oceans.        

The double star system observed by Chandra, called B1259, comprises the larger star, which the pulsar approaches every 41 months, and the pulsar, also known as a 'pulsating radio star.'

"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," explained co-author of the study Oleg Kargaltsev of GWU.

This trio of images contains evidence from NASA’s Chandra X-ray Observatory that a clump of stellar material has been jettisoned away from a double star system at incredibly high speeds.

© NASA . G.Pavlov

The team observed that in December 2011 the clump material was moving away from the B1259 star system at an average speed of seven percent of the speed of light. Between the second and third observations, in May 2013 and February 2014, the clump had accelerated to 15 percent of the speed of light. 

A pulsar, a neutron star which rotates rapidly, is the small, highly dense remnant of a much larger star which underwent a supernova explosion. The matter of a neutron star, around 20km in diameter, is so dense that a teaspoonful of it would weigh as much as Mount Everest, about one billion metric tons.