is this book a part of a series?
Yes, it is part of the Harry Potter series.
Harry Potter
Harry Potter is a series of seven fantasy novels written by British author J. K. Rowling. 
when was harry potter and the order of the phoenix published 21 June 2003 by whom is the book written? J. K. Rowling what is the story about? It follows Harry Potter's struggles through his fifth year at Hogwarts School of Witchcraft and Wizardry, including the surreptitious return of the antagonist Lord Voldemort, O.W.L. exams, and an obstructive Ministry of Magic. has this book been adapted on screen? Yes, it was released as a movie under the same name.
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Harry Potter [SEP] Introduction
Harry Potter is a series of seven fantasy novels written by British author J. K. Rowling. The novels chronicle the lives of a young wizard, Harry Potter, and his friends Hermione Granger and Ron Weasley, all of whom are students at Hogwarts School of Witchcraft and Wizardry. The main story arc concerns Harry's struggle against Lord Voldemort, a dark wizard who intends to become immortal, overthrow the wizard governing body known as the Ministry of Magic and subjugate all wizards and Muggles (non-magical people). Since the release of the first novel, "Harry Potter and the Philosopher's Stone", on 26 June 1997, the books have found immense popularity, positive reviews and commercial success worldwide.