Universe@Home

[[File:{{#setmainimage:[email protected]}}|alt=Universe@home logo image|center|frameless]]

BOINC project Universe@Home is a volunteer computing project focused on astrophysics, stellar evolution, compact objects, and gravitational-wave astronomy. The project uses the computing power donated by volunteers around the world through the BOINC platform to simulate some of the most extreme events in the Universe.

Universe@Home studies phenomena such as black holes, neutron stars, X-ray binaries, quark stars, and gravitational-wave sources detected by observatories including LIGO and Virgo. The project is hosted in Poland and has contributed to modern astrophysical research through large-scale population synthesis simulations.

The supermassive black hole in galaxy M87 photographed by the Event Horizon Telescope.

Why Universe@Home?

Modern astrophysics attempts to answer some of the biggest questions about the Universe:

• How are black holes formed?
• What happens when neutron stars collide?
• How common are gravitational-wave events?
• How do massive stars evolve and die?
• Could exotic compact objects such as quark stars exist?

These problems require enormous computational resources because scientists must simulate millions of stars and binary systems over billions of years of cosmic evolution. A single model may include stellar evolution, supernova explosions, mass transfer, accretion disks, relativistic effects, and compact object mergers.

Universe@Home allows volunteers to contribute directly to astrophysical research by donating spare CPU processing power from their computers. Instead of relying entirely on expensive supercomputers, the project distributes calculations across thousands of volunteer devices worldwide using BOINC.

The project became especially important during the era of gravitational-wave astronomy following the first direct detection of gravitational waves in 2015 by LIGO. Universe@Home simulations help scientists understand how binary black holes and neutron stars form and merge.

Visualization of a gravitational-wave signal detected by LIGO.

Goal

Universe@Home aims to model and understand the evolution of stars and compact objects throughout the Universe. The project performs large-scale simulations of stellar populations and binary systems to predict the formation and behavior of:

• Black holes
• Neutron stars
• X-ray binaries
• Compact object mergers
• Ultraluminous X-ray sources (ULXs)
• Gravitational-wave sources
• Exotic compact stars such as quark stars

One of the major challenges in astrophysics is that many important cosmic events occur over millions or billions of years and cannot be directly observed from beginning to end. By simulating enormous populations of stars and binaries, Universe@Home allows researchers to estimate event rates and compare theoretical models with real observations.

The project also creates public scientific databases containing simulation results for use by researchers and astronomy enthusiasts.

Methods

Universe@Home uses the BOINC distributed computing framework to divide enormous astrophysical simulations into smaller work units which are processed independently by volunteers' computers.

The BOINC distributed computing platform.

Most Universe@Home applications are based on advanced stellar population synthesis models which simulate the life cycles of stars and binary systems. These calculations include:

• Stellar evolution
• Binary star interactions
• Supernova explosions
• Black hole formation
• Neutron star mergers
• Accretion physics
• Gravitational-wave source evolution

The project primarily uses CPU-based computing and supports multiple operating systems including Windows and Linux. BOINC automatically downloads tasks, processes them in the background, and uploads the completed scientific results back to the project servers.

Universe@Home is particularly well suited for volunteer distributed computing because many astrophysical simulations can run independently with different initial conditions. This allows the project to efficiently scale across thousands of volunteer computers worldwide.

Artist's impression of the Cygnus X-1 black hole binary system.

The computing power donated by volunteers enables researchers to explore huge ranges of physical parameters that would otherwise require extremely expensive supercomputers.

Project team / Sponsors

Current team:

Krzysztof 'krzyszp' Piszczek, Server administrator

Original team:

Ph.D. (Astrophysics) Krzysztof Belczynski, Copernicus Astronomical Centre of the Polish Academy of Sciences, project director (passed away January 13, 2024)

Grzegorz Wiktorowicz, Astronomical Observatory of the University of Warsaw

Krzysztof 'krzyszp' Piszczek, Server administrator

Rafal Marguzewicz, Web design

Warsaw, Poland — home of several major Polish scientific institutions connected with astrophysics research.

The project has been associated with Polish scientific institutions and researchers specializing in stellar evolution, compact objects, and gravitational-wave astrophysics.

Scientific results

Universe@Home has contributed to research involving black hole populations, neutron star mergers, X-ray binaries, and gravitational-wave astronomy. Simulations from the project have helped researchers estimate compact object merger rates and explain observations from LIGO and Virgo.

The project also maintains several scientific databases available to the public.

At the moment there are six sets of data:

1. X-ray — simulations and catalogs related to X-ray binaries and compact object accretion systems.
2. QuarkStars — theoretical models involving strange quark stars and exotic compact objects.
3. Black hole database — a catalog of simulated stellar-mass black holes and their properties.
4. Dynamical formation of XRBs with black holes — studies involving the formation of black hole X-ray binaries.
5. BH NS formation database files — simulations involving black hole and neutron star binary systems.
6. Self-lensing binary predictions — predictions for binary systems producing gravitational self-lensing effects.

Artist's illustration of merging neutron stars.

List of observed black holes

Universe@Home also maintains a public catalog of observed and candidate black holes discovered through astronomical observations.

Scientific publications

Research supported by Universe@Home computations has appeared in numerous peer-reviewed publications related to compact objects, stellar evolution, and gravitational-wave astrophysics.

Illustration of the GW150914 binary black hole merger event.

1. Symmetry breaking in merging binary black holes from young massive clusters and isolated binaries Banerjee et al. 2023
2. Populations of stellar mass Black holes from binary systems Wiktorowicz et al. 2019
3. Merger of compact stars in the two-families scenario De Pietri et al. 2019
4. The observed vs total population of ULXs Wiktorowicz et al. 2019
5. Binary neutron star formation and the origin of GW170817 Belczynki et al. 2018
6. The origin of the first neutron star -- neutron star merger Belczynki et al. 2018
7. Double neutron stars: merger rates revisited Chruślińska et al. 2017
8. Strange quark stars in binaries: formation rates, mergers and explosive phenomena Wiktorowicz et al. 2017
9. The evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates of LIGO/Virgo binary black holes Belczynski et al. 2017
10. The origin of the Ultraluminous X-ray Sources Wiktorowicz et al. 2017
11. The Effect of Pair-Instability Mass Loss on Black Hole Mergers Belczynski et al. 2016
12. Spectroscopy of Kerr black holes with Earth- and space-based interferometers Berti et al. 2016
13. The first gravitational-wave source from the isolated evolution of two 40-100 Msun stars Belczynski et al. 2016
14. Nature of the Extreme Ultraluminous X-ray Sources Wiktorowicz et al. 2015

External links

• Official Universe@Home website
• Universe@Home forums
• BOINC
• Gravitational wave
• Black hole
• Neutron star
• X-ray binary