And how late is he planning to stay up reading?

Not that late.

Then by the time he decides to sleep Albus Dumbledore will be in his late thirties, around the time of World War I.

It's sort of fascinating.

He was a very interesting fellow! The biography mentions Dumbledore's family, and how his father died in Azkaban and his sister was rumoured to be a Squib and died in a duel between him and Grindelwald when they were young. He became a Hogwarts Professor when he was just shy of thirty, and was considered one of the most brilliant people to ever attend Hogwarts, winning the Barnabus Finkley Prize for Exceptional Spell-Casting, becoming the British Youth Representative to the Wizengamot, receiving a gold medal for Ground-Breaking Contribution to the International Alchemical Conference in Cairo, and publishing many papers during his studies.

And the book is there waiting for him the next day, which is a Sunday, so surely he can just continue reading...

He continues reading.

More being a Professor, prize for this and that...

—Nicolas Flamel! Who's Dumbledore's friend and partner in Alchemy research, being the sole known inventor of the Philosopher's Stone.

Is the Philosopher's Stone by any chance a small valuable object.

That book does not elaborate on its dimensions or properties but it is certainly implied to be very valuable.

There is a whole library for him to go look things up in.

Then he will soon find out that

The ancient study of alchemy is concerned with making the Philosopher's Stone, a legendary substance with astonishing powers. The Stone will transform any metal into pure gold. It also produces the Elixir of Life, which will make the drinker immortal.

There have been many reports of the Philosopher's Stone over the centuries, but the only Stone currently in existence belongs to Mr. Nicolas Flamel, the noted alchemist and opera lover. Mr. Flamel, who celebrated his six hundred and sixty-fifth birthday last year, enjoys a quiet life in Devon with his wife, Perenelle (six hundred and fifty-eight).

It is reportedly small and red and not very remarkable otherwise.

...he opens the window.

"Muninn, please find Dayo and ask him to meet me in the library."

Dayo is: brooding in the dorm room. With a black eye.

Now there's a raven on his shoulder!

He startles, then sighs. "Hi, Muninn."

"Got a book you should read."

"—okay." He gets off the couch and starts making his way outside. A few older Slytherins are in the common room and after gawking at Muninn some make a point of ignoring Dayo.

Muninn is the prettiest.

He sure is.

Up to the library.

And here is Victor. Muninn flies to his shoulder.

Victor has the book about Dumbledore open to the page mentioning Flamel and the book about the Philosopher's Stone open to the page summarizing its appearance and uses.

"What."

"Okay so why do you think this is in Hogwarts?"