We must distinguish between the Immediate Object, - i.e., the Object as represented in the sign, - and the Real (no, because perhaps the Object is altogether fictive, I must choose a different term; therefore:), say rather the Dynamical Object, which, from the nature of things, the Sign cannot express, which it can only indicate and leave the interpreter to find out by collateral experience.
As to the Object, that may mean the Object as cognized in the Sign and therefore an Idea, or it may be the Object as it is regardless of any particular aspect of it, the Object in such relations as unlimited and final study would show it to be. The former I call the Immediate Object, the latter the Dynamical Object. For the latter is the Object that Dynamical Science (or what at this day would be called "Objective" science) can investigate.
It is usual and proper to distinguish two Objects of a Sign, the Mediate without, and the Immediate within the Sign. Its Interpretant is all that the Sign conveys: acquaintance with its Object must be gained by collateral experience. The Mediate Object is the Object outside of the Sign; I call it the Dynamoid Object. The Sign must indicate it by a hint; and this hint, or its substance, is the Immediate Object. Each of these two Objects may be said to be capable of either of the three Modalities, though in the case of the Immediate Object, this is not quite literally true.
... we have to distinguish the Immediate Object, which is the Object as the Sign itself represents it, and whose Being is thus dependent upon the Representation of it in the Sign, from the Dynamical Object, which is the Reality which by some means contrives to determine the Sign to its Representation.