* Neutron stars are incredibly dense and hot. Their intense gravity pulls matter so tightly that it becomes incredibly dense, and the internal pressures generate immense heat.

* This heat causes them to emit primarily X-rays. While some faint visible light might be emitted, the vast majority of their radiation is in the X-ray spectrum.

* Visible light telescopes wouldn't be effective. Visible light telescopes are designed to detect light within the visible spectrum of light. They wouldn't be able to penetrate the vast amount of X-rays and other radiation emitted by a neutron star.

Therefore, to study the detailed structure and behavior of neutron stars, astronomers rely on powerful X-ray telescopes like Chandra, XMM-Newton, and NuSTAR.