The cordial co-operation of many amateur and professional astronomers
in the very successful observations of the Solar Eclipse of January 1, 1889, has again brought
forward the desirability of organizing an Astronomical Society of the Pacific, in order
that this pleasant and close association may not be lost, either as a scientific or as a social
force. You are respectfully invited to become a member of this organization, and to do your
part towards making it useful in our community.
This book is dedicated to the memory of Gisèle Mersch whose life ended
prematurely in June 2002. Back in the 1970s, when few people were using
them, Gisèle introduced me to the arcane secrets of then advanced multivariate
I was already involved in more classical statistical studies undertaken
at Paris Observatory with Jean Jung: developing and applying maximumlikelihood
algorithms to stellar photometric and kinematic data in order to
derive absolute luminosities, distances and velocities in the solar neighborhood....
The publication of the Hipparcos and Tycho Catalogues in 1997 transformed
astrometry, and as a consequence astronomers’ perception of astrometry. What
had before often been regarded as a somewhat quaint specialty of limited relevance
to modern astrophysics, was suddenly seen to produce a wealth of data
of immediate practical use. The ready availability of many thousand precise
trigonometric stellar distances and the access to an accurate and dense optical
reference frame have changed the way astronomers think about certain
problems and plan their experiments....