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William Herschel recorded four objects in his 1786 work " Catalogue of Nebulae and Clusters of Stars " , including two he mistakenly believed were star clusters .
 William Herschel
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 William Herschel