The distance that a telescope can "see" in terms of light years depends on various factors, including the size and capabilities of the telescope, the sensitivity of its detectors, and the specific objects being observed.
Telescopes are designed to collect and detect electromagnetic radiation across different wavelengths, including visible light, radio waves, X-rays, and more. The maximum distance a telescope can observe is often limited by the faintness of the objects being studied and the background noise or interference present.
In terms of the observable universe, the most distant objects currently observed are galaxies located billions of light years away. For instance, the Hubble Space Telescope, which has made significant contributions to our understanding of the cosmos, has observed galaxies that are more than 13 billion light years away, providing glimpses of the universe when it was relatively young.
With advancements in technology and the development of new telescopes and instruments, scientists are continually pushing the boundaries of observation. Upcoming telescopes, such as the James Webb Space Telescope (JWST), are expected to expand our view even further into the universe, potentially allowing us to observe objects and events that occurred shortly after the Big Bang.
Therefore, while there isn't a fixed limit to the distance a telescope can see in terms of light years, our current observations extend billions of light years into the universe, and future advancements hold the potential to reveal even more distant objects.