xiv
Preface
The primary aim of this book has been to document and explain the fundamental contributions of Kapteyn to astronomy in general and in the Netherlands in particular. I hope that it clarifies for non-astronomers how the field
of our developing understanding of the Milky Way Galaxy in which we live
for a major part goes back to Kapteyn and how it has developed at least
during his lifetime. The sequel on Kapteyn’s famous student Jan Hendrik
Oort carries this further to the second half of the twentieth century. For
readers more familiar with astronomy, I hope it provides or enhances appreciation for Kapteyn’s fundamental contributions to our field. In my contribution to the Legacy’ Symposium on Kapteyn that I organized in 1999 together
with historian Klaas van Berkel [4], I mentioned the following. Around 1990,
the Kapteyn Astronomical Institute instituted a ‘preprint series’. Copies of
manuscripts of papers by Groningen astronomers that had been accepted
for publication by scientific journals, but which were still in press for some
months, were copied and distributed to libraries of astronomical institutes
worldwide. The series had a cover on which a picture of Kapteyn was
displayed. Some of us on the staff were told privately and discretely by a few of
our colleagues abroad (mostly in the US) that it was inappropriate to use this
picture. After all, Kapteyn had been proven wrong in almost all respects. We
did change this to a more ‘relevant’ picture related to more current research,
but I now regret having not more strongly opposed that then.
In fact, Kapteyn was quite right in his earlier assessment that interstellar
absorption is important and in his determination of its amount. Furthermore
his analysis of the vertical structure and dynamics of the Stellar System is still
essentially correct. In his Plan of Selected Areas, he organized an all-sky survey
that made him, together with William Herschel a century earlier, one of the
godfathers of GAIA. I hope that this book and the accompanying Website
with links to other sources and publications will enhance the appreciation for
Kapteyen as a human and as an astronomer.
Groningen, The Netherlands
Original December 2014–October 2015,
Translation November 2019–May 2020.
Pieter C. van der Kruit
Emeritus Jacobus C. Kapteyn
distinguished professor of astronomy
Kapteyn Astronomical Institute
University of Groningen
https://www.astro.rug.nl/∼vdkruit
For more background and information on Kapteyn, please consult my scientific biography [5] in the Astrophysics and Space Science Library and the
dedicated Kapteyn Website www.astro.rug.nl/JCKapteyn.
Preface
The primary aim of this book has been to document and explain the fundamental contributions of Kapteyn to astronomy in general and in the Netherlands in particular. I hope that it clarifies for non-astronomers how the field
of our developing understanding of the Milky Way Galaxy in which we live
for a major part goes back to Kapteyn and how it has developed at least
during his lifetime. The sequel on Kapteyn’s famous student Jan Hendrik
Oort carries this further to the second half of the twentieth century. For
readers more familiar with astronomy, I hope it provides or enhances appreciation for Kapteyn’s fundamental contributions to our field. In my contribution to the Legacy’ Symposium on Kapteyn that I organized in 1999 together
with historian Klaas van Berkel [4], I mentioned the following. Around 1990,
the Kapteyn Astronomical Institute instituted a ‘preprint series’. Copies of
manuscripts of papers by Groningen astronomers that had been accepted
for publication by scientific journals, but which were still in press for some
months, were copied and distributed to libraries of astronomical institutes
worldwide. The series had a cover on which a picture of Kapteyn was
displayed. Some of us on the staff were told privately and discretely by a few of
our colleagues abroad (mostly in the US) that it was inappropriate to use this
picture. After all, Kapteyn had been proven wrong in almost all respects. We
did change this to a more ‘relevant’ picture related to more current research,
but I now regret having not more strongly opposed that then.
In fact, Kapteyn was quite right in his earlier assessment that interstellar
absorption is important and in his determination of its amount. Furthermore
his analysis of the vertical structure and dynamics of the Stellar System is still
essentially correct. In his Plan of Selected Areas, he organized an all-sky survey
that made him, together with William Herschel a century earlier, one of the
godfathers of GAIA. I hope that this book and the accompanying Website
with links to other sources and publications will enhance the appreciation for
Kapteyen as a human and as an astronomer.
Groningen, The Netherlands
Original December 2014–October 2015,
Translation November 2019–May 2020.
Pieter C. van der Kruit
Emeritus Jacobus C. Kapteyn
distinguished professor of astronomy
Kapteyn Astronomical Institute
University of Groningen
https://www.astro.rug.nl/∼vdkruit
For more background and information on Kapteyn, please consult my scientific biography [5] in the Astrophysics and Space Science Library and the
dedicated Kapteyn Website www.astro.rug.nl/JCKapteyn.