Tycho-Gaia and beyond - Why the first Gaia data release is special
by
Daniel Michalik(Lund University)
→
Europe/Stockholm
FB55
FB55
Description
Gaia produces a highly accurate astrometric map of galactic stars
and other celestial objects. The requirements for a good
astrometric solution for a star are not met in three situations:
- in the early phases of the space mission, when the observations sample too short a time interval;
- stars at the detection limit, which are not seen sufficiently often even throughout the full mission duration;
- and transient objects, such as supernovae, which may be observed only for a short time.
We invented methods to obtain sensible astrometric results in these
scenarios through the combination of Gaia observations with prior
information. The joint Tycho-Gaia Astrometric Solution (TGAS) and similar
methods have been demonstrated in detailed simulations, and are now
being used for the reduction of the first data reduction of Gaia. This gives the
upcoming first data release a unique character.
