For me as an archetypal astrologer the ultimate moment is the scene when Nina finally breaks past her cool perfectionism and is finally transformed into the plutonic Black Swan. It is an awesome moment. Aronofsky does an excellent job with the filming of Portman dancing up until this point. You never see her move beyond her cool perfectionism, and therefore her dancing is never very striking, and so when she finally is able to surrender to a more passionate performance it is truly impressive. And it impresses so much because the character is embodying the transformation of someone who has managed to overcome her defenses against a particular archetype (in this case Pluto), and has managed to integrate that archetype.
The archetypal combination most associated with ballet is the Venus-Saturn combination, and both Aronofsky and Portman are born with it (Aronofsky has the conjunction and Portman a tight square). Venus, of course, is ruler of art dance and music, but with Saturn it is associated more with classical art, classical music, and classical dance (Saturn's association with older things, traditional forms). And it also really fits ballet because of Saturn's association with discipline and precision, and ballet's reputation for demanding rigorous extremes of discipline (discipline of the body, discipline with food, etc.).
But for me as an astrologer, the most striking correlations are found in Portman's transits. The film started shooting in late 2009 when the Saturn square Pluto in the sky was tightly crossing Portman's natal Saturn square Venus. She was getting her exact Saturn return, and transiting Pluto was (and is) opposing her natal Venus and squaring her natal Saturn. Portman has shared that this was the most difficult role of her life. It required many months of extreme dance training and dieting, and once filming began, 16 hour days of non-stop work where she was never able to really get out of her character. Many reviewers are saying this is Portman's most mature performance, and she is very likely to receive an Oscar nomination for it.
This is all classic for her Saturn return transit, which is very often a period when you see an artists most mature and sophisticated work emerge. It is also classic for the Saturn return to bring a work situation which is extremely demanding, but which forges the full adult potential for the career. Note that Portman also began a relationship with her dance trainer from the film, and is now pregnant with his child and engaged to be married. This is all classic Saturn return stuff: the serious relationship, the taking on of the serious adult responsibilities of marriage and parenthood.
But what is really striking are the Pluto transits. It is just so classic that Pluto is crossing her natal Saturn-Venus square, as it so perfectly captures the drama and struggle that her character in the film must go through. The natal Saturn-Venus is the energy her character is possessed by (or I should say the problematic potential of Saturn-Venus is what she is possessed by). When Saturn-Venus is problematic it can be a cold-hearted armored energy which can be very perfectionistic (the perfectionistic artist, the self-critical lover), and it can also have difficulty opening to human intimacy: all qualities that Nina embodies. Pluto can intensify whatever it combines with to an extreme degree, and this is what we see in this film. Portman's character (and also Portman as an actress) takes the Saturn-Venus theme of the disciplined artist to an extreme. Also the Saturn-Venus tendency towards the armored heart is taken to a much more intense level with Pluto in the alignment, and we see Nina struggling in agony with her inability to open to passionate dance and passionate intimacy. We also really see the Pluto-Saturn archetype coming through with her slave-driving tortured discipline, and her blocked sexuality.
We see Portman embodying the Pluto-Venus archetype in many different scenes in the film (the power dynamics with the other dancers, the jealousy and envy, the forbidden sexuality with her director, and the lesbian love scene with one of the other dancers), but ultimately it comes through most powerfully in the scene I described above when she is transformed into the Black Swan. This is the moment her character moves beyond the possession state that the Venus-Saturn archetype has her in, and is able to integrate the passionate animal energies of Pluto. Of course in this case the film is a tragedy, and so Pluto also manages to destroy Nina (Venus abducted by Pluto and taken to the underworld) in the process, but still we are able to admire the courage of a character willing to give everything to move towards integration.
We have no birth time for Portman, therefore the chart above is cast for noon.