 55 Cancri is the system's Flamsteed designation. It also bears the Bayer designation Rho1 Cancri and the Bright Star Catalogue designation HR 3522. The two components are designated A and B, though A is itself sometimes referred to as 55 Cancri. The first planet discovered orbiting 55 Cancri A was designated HR 3522b by its discoverers, though it is more commonly referred to as 55 Cancri b. Under the rules for naming objects in binary star systems it should be named 55 Cancri Ab and this more formal form is occasionally used to avoid confusion with the secondary star 55 Cancri B. The other planets discovered were designated 55 Cancri c, d, e and f, in order of their discovery.
