• Harry Potter author J.K. Rowling will reveal her surprise to Potterheads at the Shanghai Film Festival.

Harry Potter author J.K. Rowling will reveal her surprise to Potterheads at the Shanghai Film Festival. (Photo : Twitter/jk_rowling)

J.K. Rowling has delighted "Harry Potter" fans yet again by revealing details about the first day of school for Harry and Ginny Potter's eldest son, James Sirius Potter.

The famed British novelist, who is known for keeping the fandom alive even long after the hit "Harry Potter" film series ended, asked her Twitter fans on Sept. 1, Tuesday to send her good luck wishes to James Sirius, who was starting at Hogwarts.

Like Us on Facebook

"I'm in Edinburgh, so could somebody at King's Cross wish James S Potter good luck for me? He's starting at Hogwarts today," the 50-year-old author tweeted.

Rowling used the hashtag "Back To Hogwarts," which was quickly embraced by fans. Some fans even became emotional as they recalled growing up with the critically-acclaimed book and film franchise.

Others played along and replied with such tweets as, "I'm on the train now. He says hi," "He's on his way," and "I met him, he's a great boy and said hi back," among others.

Still, there are fans who asked Rowling further questions about James Sirius' first day at Hogwarts, including which house Harry Potter's eldest son would be sorted into when he arrived.

Soon after, Rowling posted an update: "Have just heard that James S Potter has been Sorted (to nobody's surprise) into Gryffindor." She also mentioned another character from the "Harry Potter" universe, Teddy Lupin, who she revealed was sorted into Hufflepuff.

As any well-versed "Harry Potter" fan knows, Teddy Lupin is the son of Remus Lupin and Nymphadora Tonks, who both died during the Battle of Hogwarts shown in "Harry Potter And The Deathly Hallows: Part 2."

Rowling's recent revelations came weeks after she revealed on Twitter one truth about Rubeus Hagrid, the half-giant wizard friend of Harry Potter. On Aug. 21, the best-selling book author answered a fan's question about Hagrid's Patronus, revealing that he actually could not produce a Patronus because "it's a very difficult spell."

The revelation left many "Harry Potter" fans sad as they considered the reasons as to why Harry Potter's friend could not cast a Patronus. One reason fans believe is that Hagrid does not possess enough magical skills to be able to cast the famously difficult spell.

Another fan theory is that Hagrid cannot draw upon a happy memory that is strong enough to cast a Patronus. Fans of the "Harry Potter" wizarding world know that a wizard or witch should draw upon their happiest memory in order to produce the powerful spell.

Hence, aside from a lack of magical skill, Hagrid's lack of happy memories especially from childhood could have affected his ability to produce a Patronus charm.

Aside from sharing interesting tidbits about Harry Potter characters, the award-winning author also constantly teases fans with hints of her latest project. Currently, Rowling is busy working on the "Harry Potter" spin off movie, "Fantastic Beasts and Where to Find Them," which officially started filming in August.