[email protected], a distributed computing project searching primarily for gravitational waves, has found its first pulsar
A newfound stellar remnant some 17,000 light-years away is not your everyday pulsar. For starters, the hyperdense, swiftly pirouetting object appears to belong to a rare class known as disrupted recycled pulsars. Pulsars are so known because they rotate rapidly—this one spins more than 40 times a second—and give off a beam of radio waves that sweeps across the sky, much like a lighthouse. To an outside observer the radiation appears to pulse each time the beam points in the observer’s direction.
A disrupted recycled pulsar is a former member of a binary stellar pairing that first exploded as a supernova and collapsed to an extraordinarily dense object known as a neutron star, before cannibalizing matter from its neighbor, spinning faster all the while, and finally breaking free from its binary companion when the neighbor exploded as a supernova itself. Disrupted recycled pulsars are uncommon—a recent study estimated that of more than 1,500 known pulsars, only eight are of the disrupted recycled variety.
That life history surely qualifies as interesting, but the most noteworthy aspect of the newly located pulsar, known as PSR J2007+2722, is the way it was discovered. The celestial rarity was located by the personal computers of individuals in the U.S. and Germany who had lent their idle processor time to [email protected], a campaign that has used hundreds of thousands of volunteered computers to mine astrophysical data sets for interesting phenomena. The discovery was announced in a paper published online in Science August 12.
Volunteer computing entered the limelight in 1999 with the launch of SETI@home, a program that farms out data from radio telescopes to volunteers, whose computers automatically sift through the telescopic signals for possible signs of alien life. (SETI stands for search for extraterrestrial intelligence.) In 2002 the University of California, Berkeley, expanded the volunteer-computing platform with the launch of BOINC (for Berkeley Open Infrastructure for Network Computing), an open-source system that allowed other data-heavy projects to follow the lead of [email protected] Nowadays there are dozens of projects available through BOINC, including Climateprediction.net, which uses volunteer computers to test climate models; [email protected], which explores three-dimensional protein structures; and [email protected], which started in 2005 as a search for ripples in spacetime known as gravitational waves.