Multiple systems where the astrometric and spectroscopic orbit are known offer the unique possibility to determine the distance to these systems directly without any assumptions, and are therefore ideal objects to compare Gaia data release 3 (GDR3) parallax data with, especially since GDR3 presents the results of the non-single star (NSS) analysis that potentially results in improved parallaxes. Such an analysis is relevant in studying the parallax zero-point offset (PZPO) that is crucial in improving upon the distance scale. An sample of 192 orbital parallax determinations for 186 systems is compiled from the literature. The stars are also potentially in wide binary systems (WBS). A search was performed and 37 WBS (candidates) were found. Only for 21 objects does the NSS analysis provide information, including eight from the astrometric binary pipeline, for which the parallaxes do improve significantly on the ones in the main catalogue with significant lower goodness-of-fit (GOF) parameters. It appears that most of the objects in the sample are eliminated in the pre-filtering stage of the NSS analysis. The difference between the orbital parallax and the (best) Gaia parallax was finally performed on 170 objects. A raw comparison is meaningless however due to limitations in accuracy both in the orbital and Gaia data. As many systems have been eliminated in the pre-filtering stage of the astrometric NSS pipeline they remain in GDR3 with values for the GOF parameter in the range from several tens to several hundreds. Eliminating objects with large parallax errors or unrealistically large differences between the orbital and Gaia parallaxes, and a GOF <100 or <8 (the latter also with G<10.5mag selected), samples of 68 and 20 stars remain. Parallax differences in magnitude bins and for the sample are presented. Three recipes from the literature that calculate the PZPO are tested. After applying these corrections the remaining parallax differences are formally consistent with zero within the error bar for all three recipes. In all cases there remains an uncertainty in these averages of the order 10-15 microarcsec for these samples due to the small number statistics. The proof-of-concept of using orbital parallaxes is shown to work but the full potential is not reached as only for eight systems an improved parallax from the NSS analysis is available. In the final selection 18 of 20 stars have an orbital parallax determined to better than 5% and six have a parallax determination better than from Gaia. In the full sample 148 objects reach this precision and therefore the full potential of using orbital parallaxes may hopefully be reached with GDR4.

Cone search capability for table J/A+A/669/A4/table1 (stars: orbital elements)