telescopic

Pertaining to, or carried out by means of, a telescope.

Within a year or two of Galileo's telescopic discoveries no one disputed that the moon had mountains, Jupiter had moons, Venus had phases and the sun had spots […].

Seen by means of a telescope; only visible through a telescope.

telescopic stars

Capable of seeing distant objects; far-seeing.

Able to be extended or retracted by the use of parts that slide over one another.

telescopic baton

Referring to parts being extended or retracted along coinciding axes (with or without direct contact between the parts).