Comparison of HIPPARCOS results obtained on different dates on the same great circle
Abstract
The results on great circles that have been scanned by Hipparcos on dates separated by several months are compared. The differences in the abscissae, after correction for known proper motions and parallaxes show a noise and a systematic effect that correspond to expected inaccuracies in proper motions and parallaxes. Instrumental terms related to the position of the sun are not significantly detected, with the possible exception of a first harmonic term. If the systematic effect is entirely due to parallax, the mean value of the parallax in the observed sets of stars would be of the order of 5 milli-arcsec.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1992
- Bibcode:
- 1992A&A...258...70S
- Keywords:
-
- Accuracy;
- Comparison;
- Great Circles;
- Hipparcos Satellite;
- Satellite Observation;
- Astrometry;
- Astronomical Coordinates;
- Data Reduction;
- Sky Surveys (Astronomy);
- Astronomy