HST FGS astrometry the value of fractional millisecond of arc precision
Abstract
In a few years astrometry with the venerable combination of Hubble Space Telescope and Fine Guidance Sensor will be replaced by SIM, Gaia, and long-baseline interferometry. Until then we remain a resource of choice for sub-millisecond of arc precision optical astrometry. As examples we discuss 1) the uses which can be made of our parallaxes of Galactic Cepheids, and 2) the determination of perturbation orbital elements for several exoplanet host stars, yielding true companion masses.
- Publication:
-
A Giant Step: from Milli- to Micro-arcsecond Astrometry
- Pub Date:
- July 2008
- DOI:
- 10.1017/S1743921308018577
- Bibcode:
- 2008IAUS..248...23B
- Keywords:
-
- astrometry;
- Cepheids;
- distance scale;
- planetary systems;
- stars: low-mass;
- brown dwarfs