Gaia Data Release 3. Astrometric binary star processing

Understand

Context.The Gaia Early Data Release 3 contained the positions, parallaxes and proper motions of 1.5 billion sources, among which some did not fit well the "single star" model.

• Binarity is one of the causes of this.
• Aims.
• Four million of these stars were selected and various models were tested to detect binary stars and to derive their parameters.