January 8, 2013
New Chandra Footage Suggests That Vela Pulsar May Be Precessing
Watch the video "Chandra Captures Neutron Star In Action"
redOrbit Staff & Wire Reports - Your Universe Online
New video footage of the Vela pulsar, a neutron star located approximately 1,000 light-years from Earth, suggests that the pulsar could be slowly wobbling as it spins, NASA officials said on Monday.
Formed following the collapse of a massive star, the Vela pulsar is approximately 12 miles in diameter and capable of making a complete rotation in under 90 milliseconds. The new video, captured by NASA´s Chandra X-ray Observatory, shows the pulsar whipping about and ejecting a stream of charged particles moving along its rotation axis at approximately 70 percent the speed of light.
The footage was captured between June 2010 to September 2010. It shows that the rotating neutron star could be precessing — or behaving similarly to a tilted spinning top or gyroscope — over a period of roughly 120 days. This discovery could provide scientists with “new insight into the nature of some of the densest matter in the universe,” officials at the U.S. space agency said in a statement.
"We think the Vela pulsar is like a rotating garden sprinkler — except with the water blasting out at over half the speed of light," explained the University of Toronto´s Martin Durant, first author of a paper describing the Chandra findings, which will be published later this week by The Astrophysical Journal.
Durant and his colleagues believe that one of the possible reasons for Vela´s precession is that it has become distorted and is no longer a perfect sphere. That deviation, which co-author Oleg Kargaltsev of George Washington University (GWU) said would likely only be equivalent to one part per 100 million, could have been caused by the neutron star´s rapid rotation and what NASA refers to as “glitches” — unexpected rotational speed increases due to interaction between its superfluid core and its crust.
Kargaltsev presented the team´s findings Monday at the 221st American Astronomical Society (AAS) meeting in Long Beach, California. According to NASA, this is the second movie of the Vela pulsar that has been captured by Chandra, with the first released a decade ago.
“The first Vela movie contained shorter, unevenly spaced observations so that the changes in the jet were less pronounced and the authors did not argue that precession was occurring,” the researchers explained. “However, based on the same data, Avinash Deshpande of Arecibo Observatory in Puerto Rico and the Raman Research Institute in Bangalore, India, and the late Venkatraman Radhakrishnan, argued in a 2007 paper that the Vela pulsar might be precessing.”