333984
Observational history According to SIMBAD , WASP-13 was first observed in 1997 , when it was catalogued by astronomers measuring the proper motion of stars in regions of the sky where galaxies are detected .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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