herschel

Free Download Herschel 400 Observing Guide By Stephen James O'Meara 2013 | 379 Pages | ISBN: 1107632005 | PDF | 31 MB The Herschel 400 is a list of 400 galaxies, nebulae, and star clusters, picked from over 2,500 deep-sky objects discovered and catalogued by the great eighteenth-century...