The Bayer designation σ Ursae Majoris (Sigma Ursae Majoris, σ UMa) is shared by two star systems in the constellation Ursa Major:
They are separated by 0.33° in the sky.
The two stars, Sigma1 and Sigma2 together, are considered an optical double star. They are not a binary star, in that they are not gravitationally linked, but they are close to each other as seen in the sky.