Septima Vector

Professor Septima Vector was a witch and Professor of Arithmancy at Hogwarts School of Witchcraft and Wizardry from at least the 1993–1994 school year. She was known among students as a "really strict" teacher, so much so that some pupils were unsure whether to take her classes, and giving her pupils plenty of complicated homework. Her subject was Hermione Granger's favourite subject while she was in school.

Early life
Nothing is known about Vector's early life, though she likely attended a Wizarding School such as Hogwarts School of Witchcraft and Wizardry and excelled in Arithmancy. However, it is just as possible that she was home-schooled by her parents, though it is unknown if you could achieve an Ordinary Wizarding Level unless at a magical institution.

Career at Hogwarts
At an unknown point in her life, Vector went to Hogwarts School and applied for a teaching position there, unless the Headmaster approached her directly for her skills. Either way, she became the Professor of Arithmancy, being given Classroom 7A on the seventh floor of Hogwarts Castle to teach her lessons in, and presumably an office elsewhere on the school grounds. Her relationship to the rest of the staff is unknown, though she was considered very strict and old-fashioned by some of her students, so she may have been like Minerva McGonagall in personality.

1993
In 1993, Hermione Granger began studying Arithmancy with Professor Vector and excelled in the class. After one lesson, they had a talk about it.

1994
On September 1st, 1994, Professor Vector did not give her fourth year students any homework.

1995
"[Hagrid] waved a hand and narrowly missed concussing a frightened-looking Professor Vector, who was passing."

- Professor Vector leaving the Great Hall one morning.

When Rubeus Hagrid returned from a mission given to him by Headmaster Dumbledore, he had a conversation with Harry Potter, Ron Weasley, and Hermione Granger, Professor Vector walked past them and was almost knocked of her feet by Hagrid.

1996
In 1996, Hermione Granger thought she may had made a mistake in her homework and visited Professor Vector to discuss it.

1998
In this year the Battle of Hogwarts happened at Hogwarts. It is unknown if Professor Vector participated in fighting with the rest of the staff.

Personality and Traits
Professor Vector was described as very strict by a student who was not sure if he should take her lessons.

Name etymology
Septima most likely comes directly from Latin Septima which translates to "the seventh" (female form). As seven is the most powerful magical number, and Arithmancy deals with the numbers appearing in magic, this name suits the character well. A "vector" is a quantity, velocity for instance, specified by a magnitude and a direction.

Behind the scenes

 * Professor Vector's first name only appeared on a list of of the Hogwarts professors which was released on J. K. Rowling's website.
 * There are several unidentified female teachers who appeared in the films. One of them may be Septima.
 * Originally, she was a male named Septimus and her last name used to be Vecta.

Appearances

 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince

Notes and references
Septima Vector Септима Вектор Septima Vektor