| |
 |
| Paper: |
Combining and Comparing Astrometric Data from Different Epochs: A Case Study with Hipparcos and Nano-JASMINE |
| Volume: |
461, Astronomical Data Analysis Software and Systems XXI |
| Page: |
549 |
| Authors: |
Michalik, D.; Lindegren, L.; Hobbs, D.; Lammers, U.; Yamada, Y. |
| Abstract: |
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 Gaia will deliver some tens of
micro-arcsecond accurate astrometric parameters. Until the final Gaia 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. |
|
|
|
|
|
