We have visual detection of very few of the exoplanets we have identified. Detection by wobble gives mass and orbital period. Detection by transit gives cross

We have visual detection of very few of the exoplanets we have identified. Detection by wobble gives mass and orbital period. Detection by transit gives cross sectional area. Anything detected by transit is not a black hole, but anything we have only a detection by wobble we don't know the size, it could be a black hole.