Crowdsourcing space research

A team of scientists investigating a mysterious star system for the first time got a chance to observe one of the universe’s rarest types of stars. And thousands of people pitched in by volunteering their own computers.

The scientists from around the world report in the upcoming March edition of Monthly Notices of the Royal Astronomical Society that they discovered a rare “redback” pulsar star in a newly identified binary star system. But instead of using an optical telescope to find the system, researchers harnessed the massive computing power of the Einstein@Home project. Some half a million participants around the world have volunteered their personal computers to help parse data for scientific research. The program’s success in helping scientists locate and describe one pulsar could lead to the discovery of many more.

Scientists have known an unidentified object, which they called PSR J2039-5617, was in the area since 2014. To get a better look, lead author, University of Manchester astrophysicist Colin Clark, decided to pore over a decade of data collected from NASA’s Fermi Gamma-ray Telescope. Unlike an optical telescope, Fermi picks up particular wavelengths called gamma rays. The scientists were looking for distinctive wavelengths generated by rapidly spinning neutron stars, but that involved combing through massive amounts of data.

That’s when they decided to make use of the Einstein@Home project. Some 500,000 people have signed up to the program, which allows directors at the Max Planck Institute to harness the power of thousands of personal computers while they aren’t being actively used. This greatly increases computational capacity, allowing the network to collectively analyze data or solve problems. Together, the computers participating in the Einstein@Home project rank in the top 25 most powerful computers in the world, according to the Max Planck Institute.

Searching all the data for the distinctive gamma-ray wavelengths using one computer core would have taken about 500 years, according to the researchers. Using volunteers’ computers allowed the team to complete the research project in just two months. “It was only possible to lift the veil and discover the gamma-ray pulsations with the computing power donated by tens of thousands of volunteers to Einstein@Home,” study co-author and Max Planck Institute researcher Lars Nieder said.

The analyzed gamma rays from the Fermi Space Telescope helped scientists confirm that PSR J2039-5617 is a two-star system, and that one of the members is a rapidly rotating neutron star called a pulsar.

The universe’s oddballs, neutron stars form after a supergiant star explodes. When the remaining core of the star collapses in on itself, these incredibly dense, small stars can measure as little as 12 miles across while containing 40 percent more mass than the Sun. From there, neutron stars begin to vary. Some, called pulsars, spin rapidly while emitting strong radioactive pulses. Others, called magnetars, create intense magnetic fields capable of generating as much energy in one pulse as our Sun could emit in 100,000 years.

According to the data collected by the Fermi telescope, the pulsar at the center of PSR J2039-5617 appears to be spinning 377 revolutions per second—about the speed of some Vitamix blenders.

The star also appears to be a “redback” pulsar, consuming its binary neighbor. Named after an Australian spider, these occur when a smaller star eats a larger one. It’s so dense and spins so rapidly that it pulls matter from its neighboring star into itself. A black widow pulsar is a larger star that consumes a smaller one.

The chaos of these binary star systems means scientists have only discovered a handful of them. The matter flowing from one star to the other tends to obscure traditional methods of observation such as optical telescopes. But highly-energetic gamma rays cut through the noise, making the Fermi Gamma-ray Telescope a useful instrument to study these rare systems. The success of this discovery demonstrates that a crowdsourced computing project can handle Fermi’s massive amounts of data, potentially opening the door to finding more redback and black widow pulsars.

In the study, the researchers credit user J. Bencin of Cleveland along with another anonymous user as the volunteers whose computers first identified the celestial object.