Butterfly Cluster [SEP] discoverer or inventor
Butterfly Cluster's existence was Giovanni Battista Hodierna in 1654. However, Robert Burnham, Jr. has proposed that the 1st century astronomer Ptolemy may have seen it with the naked eye while observing its neighbor the Ptolemy Cluster (M7). Credit for the discovery is usually given to Jean-Philippe Loys de Chéseaux in 1746. Charles Messier observed the cluster on May 23, 1764 and added it to his Messier Catalog.
Estimates of the Butterfly Cluster's distance have varied over the years. Wu et al. (2009)
Fritz Klatte
Fritz Klatte (28 March 1880, Diepholz – 11 February 1934) was a German chemist and the discoverer of polyvinyl acetate, with German patent (GP 281687 1912) for its preparation from acetylene gas.
Polyvinyl chloride (PVC) was discovered by French physicist Henri Victor Regnault, and German physicist Eugen Baumann. Klatte designed the production process, although never successfully commercialised it. Klatte is sometimes incorrectly attributed to be the discoverer or inventor of PVC.
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