Einstein@Home

Einstein@Home is a volunteer computing project that searches for weak astrophysical signals from spinning neutron stars (pulsars) in data from gravitational-wave detectors, radio telescopes, and gamma-ray satellites. Neutron stars are the ultra-dense remnants of massive stars that have undergone supernova explosions — a sugar-cube-sized piece of neutron star material would weigh about a billion tons on Earth.

Rapidly spinning neutron stars can emit continuous gravitational waves — tiny ripples in spacetime predicted by Einstein's general theory of relativity. Detecting these signals requires searching over a vast parameter space of possible sky positions, frequencies, and spin-down rates, making the problem computationally enormous. Einstein@Home distributes this search across hundreds of thousands of volunteers' computers worldwide.

The project was launched in 2005 during the World Year of Physics, commemorating the centennial of Einstein's annus mirabilis. It is operated by the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Hannover, Germany, and the University of Wisconsin–Milwaukee. The project analyzes data from the LIGO and Virgo gravitational-wave observatories, the Arecibo and FAST radio telescopes, and the Fermi gamma-ray space telescope.

Einstein@Home has discovered over 90 new neutron stars, including binary pulsars, millisecond pulsars, and pulsars in previously undetected gamma-ray sources. Several of these discoveries — particularly faint, isolated pulsars with unusual spin properties — would have been virtually impossible to find without the massive computing power donated by volunteers. The project's data analysis pipelines share core signal-processing techniques with LIGO's own gravitational wave searches.

The project remains one of the most scientifically credible and productive volunteer computing efforts in the world, with results regularly published in top-tier journals including The Astrophysical Journal, Physical Review Letters, and Science.