Question: how does a supernova produce elements heavier than iron
[{'answer': 'nucleosynthesis', 'provenance': [{'wikipedia_id': '2443027', 'title': 'Supernova nucleosynthesis', 'start_paragraph_id': 0, 'start_character': 10, 'end_paragraph_id': 0, 'end_character': 25, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]