e/Butcher-Oemler Effect

Information
has gloss	eng: The Butcher-Oemler Effect is a scientific hypothesis suggesting the cores of galaxy clusters at intermediate redshift (z ~ 0.3) contain a larger fraction of blue galaxies than do the cores of low redshift clusters. The claim was first put forward by Harvey Butcher and Augustus Oemler in a 1978 Astrophysical Journal paper .
lexicalization	eng: Butcher-Oemler effect
instance of	c/Galaxy clusters