Astrometric precisions in very long baseline interferometry observations of radio stars.
Abstract
The optical and radio celestial reference frames can be linked together with radio emitting stars. Very long baseline interferometry (VLBI) observations of radio stars have been conducted and analysed since 1982 for this link. The formal uncertainties of the VLBI positions range from 0.002arcsec to a few 0.01arcsec. It is clear that large radio outbursts (>100 milliJansky) are needed to achieve an astrometric precision of 0.001arcsec with classical VLBI observations. However, these super-outbursts are relatively rare. The VLBI phase referencing technique on the other hand is more promising. When the flux density of Algol was as low as 4 milliJansky, the authors have determined its position with a milliarcsecond precision by coherently adding together 4.2 hours of data.
- Publication:
-
Processing of Scientific Data from the ESA Astrometry Satellite HIPPARCOS, 3rd FAST Thinkshop
- Pub Date:
- 1986
- Bibcode:
- 1986psde.conf..383L
- Keywords:
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- Astrometry:Radio Stars;
- Astrometry:VLB Interferometry;
- Radio Stars:Astrometry;
- VLB Interferometry:Astrometry