Nortons Star Atlas And Reference Handbook: And Reference Handbook, 20Th Edition

Nortons Star Atlas And Reference Handbook: And Reference Handbook, 20Th Edition

Excerpt. ? Reprinted by permission. All rights reserved. PrefaceThis, the 20th edition of Nortons Star Atlas, has been completely redesigned and reset to give it a fresh, modern appearance for a new century. The star charts have been relabelled to make them more legible and attractive. Among the updates and improvements to the reference handbook and its data tables, we have introduced new sections on computer-controlled telescopes and CCD imaging, both of which have changed the face of amateur astronomy in the five years since the 19th edition appeared. We have also enlarged the section on observing deep-sky objects, which are popular targets for amateurs. Other major improvements include completely new maps of the Moon and Mars. Throughout, the needs of the active observer have been kept uppermost in mind.In its previous editions, Nortons earned the reputation of being the most famous and most widely used star atlas in the world, and its reference handbook has become an indispensable companion for observers of all standards. We believe that this latest edition will carry the tradition of Nortons Star Atlas well into the twenty-first century.HistoryNortons Star Atlas first appeared in 1910. It achieved immediate success, due largely to its uniquely convenient arrangement of charts in slices, or gores, each covering approximately one-fifth of the sky, and its inclusion of stars down to sixth magnitude, the naked-eye limit. The Atlas was intended for owners of small telescopes, particularly those who wanted to find the objects of interest that were listed in two famous observing guides by nineteenth-century amateur astronomers: Celestial Objects for Common Telescopes by the Rev. T. W. Webb, and Cycle of Celestial Objects by W. H. Smyth. Over the years Nortons established an international reputation, becoming a standard reference work for amateur and professional astronomers alike.The author of the Atlas, Arthur Philip Norton (1876955), was an amateur astronomer; his full-time occupation was as a schoolmaster. Had it not been for his Atlas he would have remained almost unknown in the world of astronomy.Norton was born in Cardiff, Wales, the son of a clergyman. His interest in astronomy started when, as a schoolboy, he was given a telescope that had belonged to his great-grandfather. After receiving his BA degree from Trinity College, Dublin, he taught at various schools in England. For 22 years Norton taught geography and mathematics at the Judd School, Tonbridge, Kent, retiring in 1936. Norton published no books other than the Atlas on which his fame rests (and a simplified version, the Popular Star Atlas, which appeared in 1949), but during his lifetime it went through numerous editions, and he updated the star charts twice.Back in 1910, when Nortons Star Atlas first appeared, there were no officially recognized boundaries to the constellations a deficiency that the International Astro-nomical Union rectified in 1930. For the 5th edition of his Atlas, published in 1933, Arthur Norton redrew the charts to incorporate the newly defined IAU constellation boundaries, and he set the magnitude limit of the stars at 6.2, based on the Harvard Revised Photometry catalogue (the magnitude limit of the 1st edition had not been precisely defined). Norton by now had to cope with the fact that the sight in his left eye was badly blurred as a result of a blood clot behind the retina, but it did not affect the quality of his charts.Celestial cartographers are faced with a problem that does not afflict their terrestrial counterparts: the coordinates of all stars are gradually changing with time, because of an effect called precession. This means that all star charts are bound to become progressively out of date. The epoch (i.e. the reference date for the star positions) of the original Nortons was 1920. For the 9th edition, published in 1943, Norton redrew his charts again, this time for the standard epoch of 1950.0, and furthe