Emma Watson wished Jk Rowling a happy birthday with a sweet photo.

The 29-year-old actress - who starred as Hermione Granger in the 'Harry Potter' film franchise, which was based on books written by Rowling - took to Instagram on Wednesday (31.07.19) to share a photo of herself with the author and her 'Harry Potter' co-star Evanna Lynch in honour of Rowling's 54th birthday.

Alongside the snap - which saw the three women enjoying a fancy dress party - Emma wrote: ''Sexy and scary! You smashed this. All the love to you @jk_rowling. Happy Birthday!!!! Extra points to @Evy_Lynch for being the most perfect cat.''

In the photo, Emma sported a Wonder Woman costume while Evanna dressed up as a cat with sparkly makeup and a green dress, with the birthday girl in the middle dressed in a sleek, black dress with gory makeup.

Emma starred in all eight Harry Potter movies after being cast as Hermione Granger and worked alongside Daniel Radcliffe and Rupert Grint - who played the titular wizard and his best friend and Ron Weasely respectively - for ten years.

Since the main series of movies came to an end, Rowling certainly hasn't given up on the wizarding world, as she co-authored the two-part play 'Harry Potter and the Cursed Child' in 2015, and is working as a writer and producer on the 'Fantastic Beasts' spin-off movie franchise.

Meanwhile, it was announced in May that Rowling is working on a series of non-fiction eBook shorts called 'Harry Potter: A Journey Through...', which are adapted from the audiobook 'Harry Potter: A History of Magic'.

A statement on the Pottermore website reads: ''Prepare to delve deeper into the rich history of magic (be it our own Muggle history, or the magical world created by JK Rowling) with this new series of eBook shorts. In addition to exploring the origins of magic through history and folklore, the eBook shorts will also feature notes, manuscript pages and charming sketches as previously seen in Harry Potter: A History of Magic.''

The four ebooks are titled 'Harry Potter: A Journey Through Charms and Defence Against the Dark Arts', 'Harry Potter: A Journey Through Potions and Herbology', 'Harry Potter: A Journey Through Divination and Astronomy' and 'Harry Potter: A Journey Through Care of Magical Creatures'.

Published by Pottermore Publishing, the first two ebooks in the series were released in June, while the third was released this month, and the fourth is coming on August 22.