Pulsar Observed Wobbling Out Of Space-Time — Vanishing Out Of Our Now
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[Image via Jantoniadis]
A pulsar is a celestial object that is thought to be a rapidly rotating neutron star. The incredibly dense leftovers of a supernova, a pulsar emits regular pulses of radio waves and other electromagnetic radiation at rates of up to one thousand pulses per second. Sometimes, pulsars are locked in a ridiculously tight orbit with another star. When that happens, things can get very interesting very fast, if you're in the right position to observe it.
When a pulsar is locked in an orbit with another star, the gravity between them can become intense, so intense that it is believed by scientists to emit waves and to actually bend space-time itself, making the pulsar "wobble" in the process.
Scientists at the Netherlands Institute for Radio Astronomy have been watching Pulsar J1906 for the last five years. In that time, the astronomers determined the pulsar's weight and quantified the gravitational disturbance between it and it's paired star.
Then, all at once, the pulsar disappeared in the wink of an eye. Its beams of radio waves, like a lingering scream, are now passing by the Earth, and scientists are saying that the vanishing of Pulsar J1906 can be explained by something called "precession." Precession is when a star actually wobbles far enough that it dips into the space-time bend that its own orbit created.
Having observed this incredible occurrence firsthand, the astronomers published a paper on it in The Astrophysical Journal and were presented at the 225th meeting of the American Astronomical Society.
The lead author of the study, Joeri van Leeuwen, discussed the properties of pulsars with reporters.
"They pack more mass than our Sun has in a sphere that's only 10 miles across."
Dr. van Leeuwen continued to explain what happens when pulsars occur as binaries. He said that neutron stars "come hard up against Einstein's theory of general relativity," and generate space-time ripples called gravitational waves in the process. Though undetectable now, astronomers hope that one day they will be able to find solid evidence of the phenomenon.
The lead author said that Pulsar J1906 popped up unexpectedly during a routine survey of the sky.
"It was strange, because that part of the sky's been surveyed lots of times – and then something really bright and new appears."
The astronomers discovered the pulsar was accompanied by a companion star, and between the two of them, they were pushing the bounds of physics. The two stars circled each other in just four-hour rotations, which is the second fastest orbit ever observed. The pulsar itself spun seven times per second, blinking its two radio wave beams across space to Earth.
For the next five years, Dr. van Leeuwen's team observed over one billion rotations of the pulsar using the world's five biggest radio telescopes.
Co-author of the study, Professor Ingrid Stairs of the University of British Columbia, Canada, spoke of how the pulsar was observed.
"By precisely tracking the motion of the pulsar, we were able to measure the gravitational interaction between the two highly compact stars with extreme accuracy."
She said that both the pulsar and its binary are approximately 1.3 times heavier than our Sun, but they are only separated by one solar diameter.
"The resulting extreme gravity causes many remarkable effects."
Chief among those is the time-space warp and the wobble that has now caused J1906 to shine its light elsewhere in time — for the time being.
The pulsar's axis drifts by two degrees every year, and according to Dr. van Leeuwen's calculations, it should swing back around to shine on Earth again by about 2170.
http://www.inquisitr.com/1745673/pulsar-observed-wobbling-out-of-space-time-and-vanishing-out-of-our-now/
Space-Time Warp Hides Massive Pulsar From View After It Tips Into A 'Gravitational Well'
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This is an artist's concept of a pulsar (blue-white disk in center) pulling in matter from a nearby star (red disk at upper right). The stellar material forms a disk around the pulsar (multicolored ring) before falling on to the surface at the magnetic poles. The pulsar's intense magnetic field is represented by faint blue outlines surrounding the pulsar. NASA
A warp in the fabric of space-time has caused a pulsar in a binary star system about 25,000 light-years from Earth to vanish, at least for now, according to a team of scientists who had been monitoring the star system for over five years. The scientists reportedly estimate that the pulsar would be visible again in another 160 years after it emerges from the "gravitational well" created by its mass and rotation.
Pulsars are rotating neutron stars, which are immensely dense stars created as a result of a massive star collapsing in on itself. As a pulsar rotates, it emits high-energy radiation, similar to lighthouse casting beams of light. If this beam of high-energy radiation is pointed toward the Earth, these high-energy pulses can be detected using radio telescopes.
http://www.youtube.com/watch?v=gjLk_72V9Bw
https://www.youtube.com/watch?v=gjLk_72V9Bw
The specimen, under observation, is part of a binary star system, named J1906, which was discovered in 2004 using the Arecibo Observatory in Puerto Rico. Researchers had been studying the pulsar, which was found to have an orbital period of four hours, to determine what kind of a companion star it orbits. That is, until the pulsar vanished unexpectedly.
"These two stars each weigh more than the sun, but are still over 100 times closer together than the Earth is to the sun," Ingrid Stairs from the University of British Columbia, Canada, and a co-author of the findings published in The Astrophysical Journal, reportedly said. "The resulting extreme gravity causes many remarkable effects."
One of these "remarkable effects" is a phenomenon known as "geodetic precession." According to NASA, precession occurs when the curvature of space-time is warped by the gravity and rotation of a celestial body. As the warp increases, the body -- in this case, the pulsar -- starts wobbling and its axis of rotation shifts.
The scientists observing the pulsar said, in a statement, that as a result of the immense mutual gravitational pull created by the binary star system, the beams of radiation emitted by the pulsar were no longer aimed toward Earth.
"The pulsar is now all but invisible to even the largest telescopes on Earth. This is the first time such a young pulsar has disappeared through precession," Joeri van Leeuwen, an astrophysicist at The Netherlands Institute for Radio Astronomy and University of Amsterdam, who led the study, said in the statement. "Fortunately this cosmic spinning top is expected to wobble back into view ... but it might take as long as 160 years."
http://www.ibtimes.com/space-time-warp-hides-massive-pulsar-view-after-it-tips-gravitational-well-1779496