non-Single stars Tools


To be able to easily handle the non-single star (NSS) solutions provided for the first time in Gaia DR3, two functionalities have been developed to:

  • convert the correlation matrix and uncertaintes into the covariance matrix of the NSS solutions without bothering with the matrix indices;
  • convert the Thiele-Innes orbital elements of the astrometric solutions to the Campbell elements with uncertainties propagation.

The tool is available both in Python and in R:

Access the python version of NSS Tools here


Access the R version of NSS Tools here



Credits: The NSS Tools have been developed by N. Leclerc and C. Babusiaux, based on a software code from J.-L. Halbwachs.

Reference: Halbwachs et al., 2022, Gaia Data Release 3. Astrometric binary star processing, Astronomy and Astrophysics, Appendix A and B.