Assertion: nebula's age | /r/CapableOf | remnant rx j0852.0-4622
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Source sentences:
text: The date of the Cassiopeia A supernova event was determined from light echoes off nebulae, while the age of supernova remnant RX J0852.0-4622 was estimated from temperature measurements and the gamma ray emissions from the radioactive decay of titanium-44.