SBX originated from the migration of the SB9 catalogue, a project undertaken as part of Simon Alexandre’s Master’s thesis in Data Science at ULB in 2024/2025. This effort involved transferring the catalogue into a robust relational SQL database with well-defined constraints to guarantee data consistency and facilitate advanced querying capabilities. Enriched with high-precision astrometric data from Gaia DR3 and other external sources, SBX offers significantly improved completeness and accuracy in the positions and motions of astronomical objects. Today, the database is maintained by Simon Alexandre and Thibault Merle. A modern web interface, featuring intuitive search functions, orbital visualisations, and comprehensive data download options, has been developed to enhance accessibility and usability. The first release of SBX is online since 2025-06-24. For further details about the migration, the full manuscript is available here.
The SBX database is structured as a relational SQL schema comprising six main tables, each designed to represent a key aspect of spectroscopic binary systems and their related data. The systems table contains core properties for each binary system, such as coordinates, proper motions, parallaxes, magnitudes, and spectral types. The velocities table records radial velocity measurements for individual observations, including their epochs, velocities, errors, and other details. The orbits table stores the orbital solutions for binaries, featuring orbital periods, eccentricities, velocity amplitudes, system velocities, bibliographic references, and additional notes. The alias table maintains cross-identifications with external catalogues, recording the source catalogue, version, and identifier for each system. Finally, the configurations table captures the hierarchical structure of multiple systems, detailing family associations, parent and child relationships, and flags indicating their presence in higher-order multiples. The duplicates table lists duplicate entries uncover in SB9. Together, these tables enable robust, consistent storage and querying of astrophysical data in the SBX catalogue.
We would like to thank Cécile Loup, Gilles Landais, Anaïs Oberto, and Gregory Mantelet from CDS for their valuable discussions and assistance in setting up the Simbad Name Resolver and TAP service. We also extend our gratitude to Alain Jorissen and Sophie Van Eck from ULB for their wise advice and continued support. Finally, we express our sincere thanks to Andrei Tokovinin from CTIO for his helpful discussions regarding the planning of the SB9 migration, particularly with respect to the architecture of higher-order systems in SBX.
The Eighth catalog of the orbital elements of spectroscopic binary stars (SB8 - Batten A.H., Fletcher J.M., Mac Carthy D.G. 1989, Publ. DAO, V.17) contains the orbits published until January 1, 1988. There was no continuation of this work at DAO, hence at the 24th IAU GA (Manchester, 2000), it was decided to create a working group and update the catalog.
Unlike SB8, the new catalog SB9 will not be published on paper but will be accessible through the Internet. It will be continuously updated with new orbits.
Compilation of SB9 is done by a team of contributors worldwide. Authors of new orbits are encouraged to contribute directly. Due to the increasing volume of data, the amount of additional information per system will be reduced compared to SB8. On the other hand, SB9 includes multiple orbits per system and, when available, individual radial velocities. References are linked to the ADS bibliographic service.
We believe SB9 will be as useful as its predecessors, supporting statistical studies, target selection, and offering a comprehensive view of progress in spectroscopic binary research.
On entering the SB9 web page, users can search by object identifiers (HD, BD, HIP), bibcode, or coordinates. Uncommon identifiers can be searched via the 'Misc' option.
Each system has an internal SB9 number. The first 1439 match SB8; new numbers are assigned sequentially. If multiple orbits exist for a system, the user selects one to view.
Orbital elements are listed with formal errors when available. Fixed elements are marked with '*'. Circular orbits fix eccentricity and periastron at zero. Grades from SB8 (5-best to 1-worst) are shown for old orbits; new ones are pending an automated grading system.
In double-lined binaries, if V₀ was determined separately for primary and secondary, only the primary's value is shown.
Notes follow the orbit. When radial velocities are available, they are listed and plotted. Each includes error, weight, component ID ('a' or 'b'), and optional comments.
The SB9 working group thanks the following contributors:
We are deeply grateful for their continued support.
We are very saddened to announce that our colleague and friend Dimitri Pourbaix, the principal maintainer of the SB9 database, passed away on November 14, 2021. You may express your sympathy on this dedicated page.