Home Computers Discover Gamma-Ray Pulsars

Imagine that you’re innocently running your computer in pursuit of helping data crunch a huge science project. Then, out of the thousands of machines running the project, yours happens to stumble across a discovery. That’s what happened to several volunteers with [email protected], which seeks pulsars in data from the Fermi Gamma-Ray Space Telescope, among other projects.

“At first I was a bit dumbfounded and thought someone was playing a hoax on me. But after I did some research,” everything checked out. That someone as insignificant as myself could make a difference was amazing,” stated Kentucky resident Thomas M. Jackson, who contributed to the project.

Pulsars, a type of neutron star, are the leftovers of stars that exploded as supernovae. They rotate rapidly, with such precision in their rotation periods that they have sometimes been likened to celestial clocks. Although the discovery is exciting to the eight volunteers because they are the first to find these gamma-ray pulsars as part of a volunteer computing project, the pulsars also have some interesting scientific features.

Artist's illustration of a neutron star, a tiny remnant that remains after its predecessor star explodes. Here, the 12-mile (20-kilometer) sphere is compared with the size of Hannover, Germany. Credit: NASA's Goddard Space Flight Center
Artist’s illustration of a neutron star, a tiny remnant that remains after its predecessor star explodes. Here, the 12-mile (20-kilometer) sphere is compared with the size of Hannover, Germany. Credit: NASA’s Goddard Space Flight Center

The four pulsars were discovered in the plane of the Milky Way in an area that radio telescopes had looked at previously, but weren’t able to find themselves. This means that the pulsars are likely only visible in gamma rays, at least from the vantage point of Earth; the objects emit their radiation in a narrow direction with radio, but a wider stripe with gamma rays. (After the discoveries, astronomers used the Max Planck Institute for Radio Astronomy’s 100-meter Effelsberg radio telescope and the Australian Parkes Observatory to peer at those spots in the sky, and still saw no radio signals.)

Two of the pulsars also “hiccup” or exhibit a pulsar glitch, when the rotation sped up and then fell back to the usual rotation period a few weeks later. Astronomers are still learning more about these glitches, but they do know that most of them happen in young pulsars. All four pulsars are likely between 30,000 and 60,000 years old.

Artist's conception of a gamma-ray pulsar. Gamma rays are shown in purple, and radio radiation in green. Credit: NASA/Fermi/Cruz de Wilde
Artist’s conception of a gamma-ray pulsar. Gamma rays are shown in purple, and radio radiation in green. Credit: NASA/Fermi/Cruz de Wilde

“The first-time discovery of gamma-ray pulsars by [email protected] is a milestone – not only for us but also for our project volunteers. It shows that everyone with a computer can contribute to cutting-edge science and make astronomical discoveries,” stated co-author Bruce Allen, principal investigator of [email protected] “I’m hoping that our enthusiasm will inspire more people to help us with making further discoveries.”

[email protected] is run jointly by the Center for Gravitation and Cosmology at the University of Wisconsin–Milwaukee and the Albert Einstein Institute in Hannover, Germany. It is funded by the National Science Foundation and the Max Planck Society. As for the volunteers, their names were mentioned in the scientific literature and they also received certificates of discovery for their work.

Source: Max Planck Institute for Gravitational Physics

[email protected] Citizen Scientists Discover Weird Pulsar

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Hooray for citizen scientists! The [email protected] project has discovered a unusual pulsar approximately 17,000 light-years away in the constellation Vulpecula. The project works by people “donating” idle time on their home computers. This is the first deep-space discovery by [email protected], and the finding is credited to Chris and Helen Colvin, from Ames, Iowa in the US, and Daniel Gebhardt of Universitat Mainz, Musikinformatik,Germany.

The newly discovered pulsar, PSR J2007+2722, is an isolated neutron star that rotates 41 times per second and has an unusually low magnetic field.

Jim Cordes, Cornell professor of astronomy, said the object is particularly interesting because it is likely a recycled pulsar: a neutron star that once had a companion star from which it acquired mass; but whose companion exploded, kicking it free.

Unlike most pulsars that spin as quickly and steadily, PSR J2007+2722 sits alone in space, and has no orbiting companion star. However, the scientists say they can not rule out that it may be a young pulsar born with an lower-than-usual magnetic field.

“We think there should be more of these disrupted binary pulsars, but there haven’t been that many found,” said Cordes. “No matter what else we find out about it, this pulsar is bound to be extremely interesting for understanding the basic physics of neutron stars and how they form.”

The discovery demonstrates the power of the network used to collect and sort through vast amounts of data, Cordes said.

[email protected] was originally organized to find gravitational waves — ripples in space-time — using the Laser Interferometer Gravitational Wave Observatory (LIGO). In 2009, data from the Arecibo Observatory were included in the processing.

Chris and Helen Colvin who were credited with discovering a new pulsar. Image courtesy Chris Colvin.

[email protected] is based at the Center for Gravitation and Cosmology at the University of Wisconsin-Milwaukee and at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, or AEI) in
Hannover, Germany. About one-third of [email protected]’s computing capacity is used to search Arecibo data.

[email protected] volunteer Daniel Gebhardt from Germany. Image couresty of Gebhardt.


“This is a thrilling moment for [email protected] and our volunteers. It proves that public participation can discover new things in our universe,” said Bruce Allen, leader of the [email protected] project, AEI director and adjunct professor of physics at the University of Wisconsin-Milwaukee. “I hope it inspires more people to join us to help find other secrets hidden in the data.”

Gebhardt and the Colvins will receive plaques noting their discovery, and all plan to stay involved.

For information on how you can get involved in the project, see the [email protected] website.

Sources: Cornell University, ScienceExpress.

On a related note, check out these Albert Einstein quotes.