The Sun travels alone through space without a stellar companion. Most stars, however, have at least one gravitationally bound partner. A new study posted on the arXiv preprint server by researchers at the University of Madrid provides a detailed classification of nearly all stars within 10 parsecs and offers data useful for future exoplanet searches.
The survey covers objects out to 10 parsecs, or about 32.6 light years. This distance limit helps ensure completeness because companions become harder to detect at greater ranges. Researchers combined data from the European Space Agency’s Gaia DR3 release with the Washington Double Star Catalog, which contains decades of radial-velocity observations. The final catalog lists 424 known stellar and substellar objects inside the 10-parsec volume. Of these, 215 objects belong to 92 multiple-star systems.
Among the 92 systems, 68 are binaries, 19 are triples, three are quadruples, and two are quintuples. The study also found a clear link between stellar mass and multiplicity. Stars more massive than half a solar mass have a 41 percent chance of having at least one companion. In contrast, objects below 0.1 solar masses, such as red and brown dwarfs, show only a 9 percent rate of multiplicity.
Orbital periods vary widely. Some pairs complete orbits in days, while others require tens of millions of years. Even the widest pairs were confirmed as gravitationally bound through binding-energy calculations.
The catalog supports studies of star formation and aids searches for habitable exoplanets. Companion stars can distort radial-velocity signals and add noise to direct-imaging observations planned by future missions such as NASA’s Habitable Worlds Observatory and ESA’s LIFE interferometer. The vetted list of nearby systems therefore serves as a reference for these upcoming telescopes.
