a small, low-power telescope with a cross-hair in it which is used to locate celestial objects

A small, low-power telescope attached parallel to the main telescope that aids in locating celestial objects and in pointing a telescope.

A finderscope (or finder) is a low-power telescope attached to (and aligned with) a higher-power telescope. The finder is used to locate objects in the sky easily; the higher-power telescope is then used for closer examination.

A Finderscope is a small auxiliary telescope mounted atop the main astronomical telescope and pointed in the same direction. The finderscope usually has a much smaller magnification than the main telescope can provide and therefore can see more of the sky. This helps in locating the desired astronomical object in the night sky.