Assertion: supernova | /r/MadeOf | either chemical imbalance
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: A nova usually occurs in binary star systems when a white dwarf absorbs a lot of matter; where as a supernova can be formed by either chemical imbalance or core implosion.
text: A supernova is usually formed after either a chemical imbalance, or due to implosion of the core of the host star.(6)