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Binary stars in action

July 2011: You can witness some visual double stars complete much of their orbits within your lifetime.
binary-star
Visual binary star 70 Ophiuchi has an orbital period of nearly 88 years. It's currently approaching "apastron," a position where the two components are as far away from each other as they get. Astronomy: Roen Kelly, after Richard Dibon-Smith
Can an amateur astronomer with a backyard telescope perceive the orbital motion of a binary star in a reasonably brief period? Gene Crist of Peoria, Arizona, wants to know. “Are you aware of any visual binaries that are short period?” he e-mailed. “By short period, I mean they have a complete orbit that takes 20 years or less; something I could possibly observe in my lifetime.”

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