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Our speaker on March 26 will be Steve Gottlieb who is working on improving the NGC and IC databases. The talk starts at 8 p.m. and all are welcome. There is no charge and the talks are held at Hogue Park. In 1864, a General Catalog of nebulae was published which included around 2500 objects cataloged by William Herschel and an equal number from his son, John. Work from other observers was added creating a 7800 entry database called the New General Catalog (NGC) of Nebulae and published by J. Dreyer. Updates came in the form of Index Catalogs (IC). Between the NGC and IC there are more than 13,000 objects of which 90% are actually galaxies. (The distinction between "spiral nebulae" and galaxies was not made clear until Hubble's discoveries in 1923). Some items in the NGC are also known as Messier objects. For example, M31 = NGC 224. Steve Gottlieb's 25 years as an astronomer includes working on catalogues and is an active member of SFAA. He has written a number of deep-sky observing articles including articles for Sky & Telescope and Astronomy magazines. He has a deep-sky website with Jim Shields called Adventures in Deep space. |