yes it looks like ledge graduated a year under him, so close and probably definitely knew one another or at least of one another. man that one year was a doozy huh? ledger here is a bit different in he was a slytherin not quite like many others, he didn't come from a great deal of money and is a half blood, but he makes up for it in cleverness and snide commentary, and was for most of his years at hogwarts a much better quidditch player than he ever was a wizard! post hogwarts he struggled around and partied a bit too much and ended up a werewolf, but that unhappy curse ended up helping him secure a national team spot, where he now has played for puddlmere united for a long time, like a long time, and works as a werewolf-wizard liaison for the ministry as a bit of a poster boy for how well being a werewolf can go (spoiler: well enough)