The Legacy Of J C Kapteyn

Jacobus Cornelius Kapteyn (1851-1922) of the University of Groningen was one of the foremost astronomers of his time, resulting in a leading role internationally of Dutch astronomy throughout the twentieth century. This volume, which is the proceedings of a special `legacy' symposium at the celebration of the 385th anniversary of the University of Groningen, addresses Kapteyn's influence on the development of modern astronomy through studies of his pioneering work on statistical astronomy and the Structure of the Sidereal System, and his leadership in establishing international collaborations, in particular the Plan of Selected Areas. In addition to historical studies related to Kapteyn's person, work, international collaborations and organisational efforts, the volume discusses the influence of Kapteyn on the internationalisation of astronomy and on contemporary astronomy. It also provides an inventory of Kapteyn's correspondence.

Jacobus C. Kapteyn (1851-1922) was a Dutch astronomer who contributed heavily to major catalogs of star positions, such as the Cape Photographic Durchmusterung and the Harvard-Groningen Durchmusterung, and arranged extensive international collaboration through his Plan of Selected Areas. He contributed to the establishment of statistical astronomy and structure and dynamics of the Sidereal System. All aspects of Kapteyn’s life are discussed, from his birth in Barneveld, the Netherlands, to his death in Amsterdam, and his entire resume of scientific achievements in between. Kapteyn had some conflicts with others in his field, especially after the world became divided on how to handle scientific contributions from Germany post-World War I. Both Kapteyn's struggles and achievements are written against the backdrop of both the historical context of the world at that time as well as the scientific one.

This non-technical biography of Jacobus Cornelius Kapteyn (1851-1922) presents to the general reader the scientific life of the astronomer who pioneered the studies of the structure of the Milky Way Galaxy. In telling Kapteyn’s story the author weaves in astronomy basics and uses modern astronomical images to show the developments of astronomical research from Kapteyn’s times to the present. In particular the study of the distribution of stars in space has now culminated with spectacular new insights coming from the astrometric satellite GAIA, which is receiving much public attention today. The biography shows how Kapteyn’s ideas influenced prominent astronomers worldwide. He is prominent as designer of the Kapteyn Universe, the alternative to the large system found by Harlow Shapley. He is the discoverer of Kapteyn’s Star, still the second fastest moving star in the sky, which is now one of the nearest stars with a planet in the habitable zone. This fascinating hybrid of astronomy history and popular astronomy tells the story of the astronomy professor without an observatory who founded the first astronomical laboratory specializing in measuring photographic plates exposed elsewhere. Kapteyn took astronomy out of cataloguing stars to measuring distances and velocities in order to study their spatial distribution, systematic motions (Kapteyn’s Star Streams) and the equilibrium between their gravity and motions. His legacy includes, in addition to the first application of Galactic structure and dynamics, Jan Hendrik Oort, the famous astronomer from Leiden, who as a student was so impressed by Kapteyn’s lectures that he decided to become an astronomer.

This is a thorough, very readable and excellently illustrated biography of Willem de Sitter (1872-1934), one of the most influential astronomers of his time, and also a co-author and correspondent of Einstein. Authored by a physicist and skilled writer, the book gives a beautiful and accessible description of the physics debated by Einstein and de Sitter, as well as the latter's alternative cosmological model, later known as the De Sitter Universe. But this is just part of a fascinating and varied life story involving numerous contributions to astronomy, as well as many places and personalities of early 20th century physics. The book will appeal to all those interested in astronomy and physics and their history.

Our understanding of galaxy formation comes mostly from two sources: sensitive observations at high angular resolution of the high-redshift Universe, where galaxies are observed to be forming, and detailed observations of individual stars and clouds in the Local Group, where telltale remnants from its formative time remain and similar processes operate at a low level today. The current conference focusses on key aspects of the Local Group, composed of the Milky Way, Andromeda and Triangulum Spiral Galaxies, the Large and Small Magellanic Cloud galaxies, numerous dwarf and irregular galaxies, and intergalactic gas. Topics include the halo and thick disk of the Milky Way with its first stars and stellar streams; the Milky Way bar, bulge and outer edge; interstellar dust and turbulence; star formation processes and stellar scattering in spiral arms; views through the infrared Eyes of the Spitzer Space Telescope; globular clusters; the Local Gould Belt; stellar metallicities and elemental abundances; the environment and black hole in the Milky Way nucleus; orbits of the Magellanic Clouds and galaxy dwarfs; interstellar dust and turbulence; the outer disks and halos of the Andromeda and Triangulum galaxies; ripples from a collision in Andromeda; and arcs of carbon stars in the Triangulum and intergalactic clouds. This volume also discusses surveys of planetary nebulae, galaxy morphology at low and high redshift, cosmic evolution of star and galaxy formation and gas accretion, Lyman alpha emitting galaxies, ultra-low surface brightness imaging, and more. Readers are given a clear and comprehensive view of this wide range of topics written by specialists in each field. This is the proceedings of an International Conference at the Seychelles archipelago in May 2014, on the occasion of the 60th birthday of David Block and the millionth (base two) birthday of Bruce Elmegreen.

Today, we accept that we live on a planet circling the sun, that our sun is just one of billions of stars in the galaxy we call the Milky Way, and that our galaxy is but one of billions born out of the big bang. Yet as recently as the early twentieth century, the general public and even astronomers had vague and confused notions about what lay beyo

An insider's view of how the massive black hole was discovered at the Galactic Center.