Galactic Encounters

Written by William Sheehan, a noted historian of astronomy, and Christopher J. Conselice, a professional astronomer specializing in galaxies in the early universe, this book tells the story of how astronomers have pieced together what is known about the vast and complicated systems of stars and dust known as galaxies. The first galaxies appeared as violently disturbed exotic objects when the Universe was only a few 100 million years old. From that tortured beginning, they have evolved though processes of accretion, merging and star formation into the majestic spirals and massive ellipticals that dominate our local part of the Universe. This of course includes the Milky Way, to which the Sun and Solar System belong; it is our galactic home, and the only galaxy we will ever know from the inside. Sheehan and Conselice show how astronomers’ understanding has grown from the early catalogs of Charles Messier and William Herschel; developed through the pioneeringefforts of astronomers like E.E. Barnard, V.M. Slipher, Henrietta Leavitt, Edwin Hubble and W.W. Morgan; and finally is reaching fruition in cutting-edge research with state-of-the-art instruments such as the Hubble Space Telescope that can see back to nearly the beginning of the Universe. By combining archival research that reveals fascinating details about the personalities, rivalries and insights of the astronomers who created extragalactic astronomy with the latest data gleaned from a host of observa tions, the authors provide a view of galaxies – and their place in our understanding of the Universe – as they have never been seen before.