Strange pulsar found by volunteer army
MORE THAN 100,000 BUDDING Einsteins across the world have helped an international team of scientists to discover a rare pulsar, just by leaving their computers switched on. The rapidly rotating pulsar is unusual because it is not accompanied by a companion star, typical of most pulsars.
The results of the discovery, published in the journal Science today, are the culmination of an international effort led by Bruce Allen, Jim Cordes and graduate student Benjamin Knispel from the Max-Planck Institute for Gravitational Physics in Hannover, Germany, and involving scientists at Melbourne’s Swinburne University of Technology.
“We wanted to find something that is really exotic, because that will transform our understanding,” says Dr Ramesh Bhat from Swinburne’s Centre for Astrophysics and Supercomputing. This was one of five centres worldwide that helped process telescopic survey data through supercomputers, to search for pulsars.
“We wanted to find a pulsar rotating very-very fast, and that requires [supercomputing] power,” he told Australian Geographic.
A pulsar is a highly magnetised neutron star that emits a beam of electromagnetic radiation as it rotates. It’s something like a “fast-spinning cosmic lighthouse,” explains Benjamin. Although extremely compact with diameters of around 20 km, neutron stars can have a mass 1.5 times that of our Sun, making them among the densest objects in the universe.
Benjamin says the pulsar, known as PSR J2007+2722, was identified from survey data taken in February 2007 at the Arecibo Observatory in Puerto Rico. It was likely formed from a binary star system in which both stars went through supernova explosions before one turned into a pulsar and the other was either absorbed or spun off into space by the force of the explosion.
“Systems like these are quite rare; with this new discovery, only 13 out of the approximately 1900 known pulsars are of this kind. Thus, any discovery can help further our understanding of the evolution of these objects,” he says.
While the participating scientists used supercomputers to process data, they also relied on the public’s help through the Einstein@Home “volunteer computing” project, in which volunteers give scientists access to their PCs and laptops to conduct research as the machines sit idle.
Ramesh believes the pulsar’s discovery proves that volunteer computing holds great potential for science: “Volunteer computing makes a real difference to science but it also gets ordinary people involved and interested in the work we’re doing.”
Dr Dick Manchester from the CSIRO, a world expert on pulsars, agrees the project is significant because it marks the “first time [volunteer computing] has been used for finding radio pulsars.” As the technology improves, this form of scientific research will only become more important, he says.
The aggregate computing power achieved by Einstein@Home places it among the top 20 supercomputers in the world. That’s because the program is spread over the globe – in volunteer’s homes, offices, schools and universities – reducing system administration and running costs.
Einstein@Home is one of over 50 volunteer computing projects currently supporting scientific research from institutions around the world, including in biomedical research, particle physics, climate research, and seismology.