Mu1 Cancri (Latinised as Mu¹ Cancri and abbreviated μ¹ Cnc) is a stellar designation in the constellation Cancer. It forms one component of the double star system traditionally catalogued under the Bayer designation μ Cancri, the other component being μ² Cancri. The two stars are listed separately in astronomical catalogs and are identified by their positions in the sky with right ascension and declination coordinates defined for the standard epoch J2000.0.
The name follows the Bayer nomenclature, wherein Greek letters are assigned to stars within a constellation, with superscript numbers used when a Bayer letter applies to multiple nearby stars. As such, μ¹ Cancri is a recognized, though relatively faint, point of light in the night sky; its apparent visual magnitude places it near the limit of naked‑eye visibility under dark‑sky conditions.
Beyond its identification as a component of the μ Cancri pair, detailed encyclopedic information—such as precise spectral classification, parallax‑derived distance, astrophysical parameters, and historical observations—is not widely documented in major reference works. Consequently, comprehensive data on Mu1 Cancri’s physical characteristics remain limited in publicly accessible astronomical literature.