Question: who was the first man to classify stars according to their brightness
[{'answer': 'the Greek astronomer Hipparchus', 'provenance': [{'wikipedia_id': '2500686', 'title': 'Magnitude (astronomy)', 'start_paragraph_id': 6, 'start_character': 54, 'end_paragraph_id': 6, 'end_character': 85, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': 'or the Alexandrian astronomer Ptolemy', 'provenance': [{'wikipedia_id': '2500686', 'title': 'Magnitude (astronomy)', 'start_paragraph_id': 6, 'start_character': 87, 'end_paragraph_id': 6, 'end_character': 124, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '2500686', 'title': 'Magnitude (astronomy)', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 545, 'bleu_score': 0.977397480575333, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8412939259429370676}, 'section': 'Section::::History.\n'}]}]