81637
The " red clump " is a clustering of red giants in the Hertzsprung–Russell diagram at around 5,000 K and absolute magnitude ( M ) + 0.5 , slightly hotter than most red-giant-branch stars of the same luminosity .
 Hertzsprung–Russell
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Hertzsprung–Russell