Thornton laughed at the Professor's exclamation, his shoulders shaking as he tried to stifle it.

But Thornton didn't recognize that title, which he thought odd, given the library at home. "Is that a muggle book, professor?" he asked, curiously. He wondered if he'd be permitted to have a copy. It wasn't that his parents had anything against muggles, but they weren't exactly fond of muggle things in the house.

Nodding at the information about the constellation, Thornton flipped through his book until the page on Grus was visible. Reading aloud, he mumbled to himself. "Fully visible south of latitude 33N, Grus has twelve stars and is one of the southern birds, along with Phoenix, Tucana and Pavo."*

Face screwed up in concentration, Thornton flipped through the book to locate the other constellations. Peering at the simple line renderings in the book and then starting back up at the ceiling, Thornton lost himself in the search for the other birds.

*ooc: whatup, Wikipedia