X-ray telescopes are specialized instruments designed to observe high-energy radiation emitted by celestial objects, such as black holes, neutron stars, and supernova remnants. Unlike optical telescopes that capture visible light, X-ray telescopes use mirrors and detectors to focus and measure X-rays, which are a form of electromagnetic radiation with much shorter wavelengths. These telescopes are often placed in space to avoid the Earth's atmosphere, which absorbs X-rays and prevents them from reaching the ground. Notable examples include the Chandra X-ray Observatory and the XMM-Newton, both of which have provided valuable insights into the universe's most energetic phenomena.