I like that movie with Rachel Weisz, I like it a lot,
but it's not a strictly historical documentation, it's a work of imagination. There is no evidence that Hypatia was interested in the theory of heliocentrism. She certainly could have been. But we don't have any evidence of it.
We know for sure, though, that the destruction of the library at Alexandria and the murder of Hypatia did not happen in the same big riot. In AD 391 the Coptic Pope Theophilus (who was not one of the Roman Catholic Popes, the title "Pope" was used separately by Copts) ordered the destruction of the Serapeum, a pagan temple in Alexandria which may or may not have still contained a part of the great library's collection of manuscripts. No contemporary accounts of the destruction of the Serapeum mention the library. Hypatia was killed in 415 or 416, and contrary not only to Agora but also to many other films, novels, paintings and pseudo-historical books, she was likely around 60 years old at the time.
The Library might have been gone long before Hypatia was born. It might have been destroyed once, or badly damaged and then restored several times. Plutarch, Aulus Gellius, Ammianus and Orosius all claim that Julius Caesar destroyed the library in 48 BC when he was besieging Alexandria and set fires to his own ships and the fire spread first to the docks and then further into the city.
The next major candidate, chronologically, for the destruction of the library is the war in the 270's when the Emperor Aurelian suppressed a revolt led by Queen Zenobia of Palmyra. In the course of this war parts of the city which may have contained the library were badly damaged.
Then comes AD 391 and the closing of the Serapeum.
Then there was the Muslim conquest of Alexandria in 642. Several Muslim accounts of that conquest state that the great library was still there when the Muslims arrived, and was destroyed by them. However, the earliest of these accounts was written more than 500 years after the fact.
I think I can sum this up very nicely for you: anyone who says that they know when and how the library at Alexandria was destroyed, is wrong.
I might as well add: anyone who says that they know how big that library was, and how great the culture loss was when it was destroyed, is wrong also. Yes, it's quite reasonable to envision it as a very great and very regrettable loss. But there have been a very great number of losses of ancient Classical literature, occurring over many centuries, from Ireland to India. The cultural loss at Alexandria is just a small part of the overall loss.
But chin up, because some of that stuff is being re-discovered! Most spectacularly in the papyri found at Oxyrhynchus.