A telescope that gathers radiation with a metal dish is a radio telescope.

Here's why:

* Radio waves: Radio telescopes are designed to detect radio waves, a type of electromagnetic radiation.

* Large dish: The metal dish acts as a large antenna, focusing the incoming radio waves onto a receiver at its focal point. This allows for a greater concentration of the signal, making it easier to detect.

* Different from optical telescopes: Optical telescopes use mirrors to collect and focus visible light, while radio telescopes use dishes to collect radio waves.

Let me know if you have any other questions!