Finding "absolute" parallaxes directly
Received 3 January 1996 / Accepted 17 June 1996
We develop the formalism for estimating parallaxes, proper motions and positions from long-focus astrometric observations as well as additional extraneous reference material whenever this is available and relax the constraints on the star parameters (basically their sums and correlations with the coordinates on the frames), thus generating (albeit correlated) quasi-observations whose inclusion would make the solutions determinate even if there were no extraneous reference material. The result are data on the same system to which the reference material is referred, so that there is no need to perform the "reduction from relative to absolute" as an afterthought.
Key words: astrometry methods: analytical; data analysis
© European Southern Observatory (ESO) 1997
Online publication: April 8, 1998