By Vivien Lee
Anyone can discover a neutron star in their own home, says the director of the Einstein@Home Project, Prof Bruce Allen. You don’t even have to be awake—your computer screensaver does it for you. In fact, it’s already been done.
In August, a couple in Iowa, USA and a man in Mainz, Germany made Einstein@Home’s first discovery, a speedy neutron star that spins 41 times a second compared with the typical once per second.
The Einstein@Home project harnesses the power of personal computers all over the world to analyse vast amounts of experimental data collected by radio telescopes. What the physicists are searching for are ripples of time and space known as gravitational waves, as well as neutron stars—super-dense astronomical objects somewhere between a regular star and a black hole.
More than 250,000 volunteers world-wide have downloaded the Einstein@Home software which switches their computers to analysing data when they are otherwise idle.
A second discovery has since been made, but details are still under wraps, awaiting formal verification before the home astronomers are told.
The Einstein@Home software is freely available for download through the website, einsteinathome.org
The Einstein@Home search for new neutron stars
Max Planck Institute for Gravitational Physics, (Albert Einstein Institute) Callinstrasse 38, 30167 Hannover, Germany
Einstein@Home is a volunteer distributed computing project with more than a quarter-million participants. This talk will describe the current status of its search for new neutron stars, using data from gravitational-wave and radio observatories.
Einstein@Home is a volunteer distributed computing project, with volunteers from all 192 countries recognized by the United Nations. Members of the general public can go to the Einstein@Home web site  and “sign up” their computers to the project. After creating an account with a username, password and email address, they download and install a simple program, available for Windows, Macs and Linux. This process takes about two minutes for a non-technical user. Afterwards, no further action is needed by the volunteer.
One installed as described above, the program functions as a screen-saver. When the volunteer’s computer is otherwise idle, it downloads physics data from the Einstein@Home servers servers at the University of Wisconsin – Milwauke and at the Max Planck Institute for Gravitational Physics in Hannover, Germany. The program analyzes the data on the volunteer’s computer, searching it for weak signals, then returns the results to the Einstein@Home servers.
Einstein@Home was launched in 2005, as part of the activities of the World Year of Physics 2005. Since that time, more than 250,000 individuals have contributed computing cycles to Einstein@Home. Each week, more than 100,000 computers contact the Einstein@Home servers to download data for analysis. The aggregate computing power of these machines currently exceeds 300 Tflop/s (Trillion floating point operations/sec). This puts Einstein@Home on par with the largest available supercomputers.
Since 2005, Einstein@Home has been analyzing data from the Laser Interferometer Gravitational -wave Observatory (LIGO) in the United States, searching for the very weak continuous gravitational-wave signals that would be produced by nonaxisymmetric neutron stars rotating tens to hundreds of times per second. So far this work has not detected any gravitational waves, but has produced sensitive upper limits on the gravitational-wave strain amplitude produced by unknown neutron stars. The published upper limits analyze thousands of hours of the most sensitive LIGO data from LIGO’s fourth  and fifth  science runs, S4 and S5. Additional papers are forthcoming.
Since 2009, in parallel with the previous analysis, Einstein@Home has also been analyzing radio data from the Arecibo Observatory, the world’s largest single-dish radio antenna, located in Puerto Rico. This Einstein@Home analysis is currently being carried out using data from the PALFA collaboration at Arecibo. It searches short stretches of data (a few minutes long) looking for the periodic pulsing signals that are produced by the electromagnetic emission from magnetized neutron stars.
The Einstein@Home radio pulsar search pipeline is designed to detect the emission from pulsars in short-period binary systems, with orbital periods as short as 11 minutes. The analysis does a full demodulation to remove orbital effects. Such analysis is made possible because Einstein@Home has enormous computing power, and would not be possible with more conventional data analysis resources.
In August 2010, the Einstein@Home project announced the discovery of a new 40.8 Hz radio pulsar in Arecibo data . Further discoveries are expected.
This talk will describe these two different Einstein@Home searches, and report on the current status and the latest results.
 Einstein@Home web site is http://einstein.phys.uwm.edu/.
 B.P. Abbott, et al.; Einstein@home search for periodic gravitational waves in LIGO S4 data, Phys. Rev. D79, 022001 (2009).
 B.P. Abbott, et al.; Einstein@Home search for periodic gravitational waves in early S5 LIGO data, Phys. Rev. D80, 042003 (2009).
 B. Knispel, B. Allen, J. M. Cordes, J. S. Deneva, et. al., Pulsar discovery by global volunteer computing, Science Vol. 329. no. 5997, p.1305 (2010).
Bruce Allen, email@example.com