Combining and Comparing Astrometric Data from Different Epochs: A Case Study with Hipparcos and Nano-JASMINE

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding


The Hipparcos mission (1989-1993) resulted in the first space-based stellar catalogue including measurements of positions, parallaxes and annual proper motions accurate to about one milli-arcsecond. More space astrometry missions will follow in the near future. The ultra-small Japanese mission Nano-JASMINE (launch in late 2013) will determine positions and annual proper motions with some milli-arcsecond accuracy. In mid 2013 the next-generation ESA mission Gala will deliver some tens of micro-arcsecond accurate astrometric parameters. Until the final Gala catalogue is published in early 2020 the best way of improving proper motion values is the combination of positions from different missions separated by long time intervals. Rather than comparing positions from separately reduced catalogues, we propose an optimal method to combine the information from the different data sets by making a joint astrometric solution. This allows to obtain good results even when each data set alone is insufficient for an accurate reduction. We demonstrate our method by combining Hipparcos and simulated Nano-JASMINE data in a joint solution. We show a significant improvement over the conventional catalogue combination.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Astronomy, Astrophysics and Cosmology
Original languageEnglish
Title of host publicationAstronomical Data Analysis Software and Systems XXI (ASP Conference Series)
PublisherAstronomical Society of the Pacific
Publication statusPublished - 2012
Publication categoryResearch
Event21st Annual Conference on Astronomical Data Analysis Software and Systems - Paris, France
Duration: 2011 Nov 62011 Nov 10

Publication series



Conference21st Annual Conference on Astronomical Data Analysis Software and Systems