a scientific instrument that magnifies an image

a device that controls amount of light admitted

optical device that helps a user to find the target of interest

optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image

any telescope designed to collect and record electromagnetic radiation from cosmic sources

a small telescope attached to a large telescope to use in setting the line of the larger one

a telescope whose mounting has only two axes of motion, one parallel to the Earth's axis and the other one at right angles to it

a telescope designed to make observations of the sun

a telescope mounted on an axis running east and west and used to time the transit of a celestial body across the meridian

a device that controls amount of light admitted

optical device that helps a user to find the target of interest

optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image