Stars primarily emit infrared radiation, which is considered long-wavelength radiation compared to visible light.

Here's why:

* Stars have a range of temperatures: Different stars have different surface temperatures. While hotter stars emit a significant amount of visible light, cooler stars emit more radiation in the infrared spectrum.

* Infrared radiation is long-wavelength: Infrared radiation has wavelengths longer than visible light. This means it carries less energy per photon.

* Wien's Displacement Law: This law states that the peak wavelength of radiation emitted by a blackbody is inversely proportional to its temperature. Cooler stars have longer peak wavelengths, falling into the infrared portion of the electromagnetic spectrum.

While stars emit across the entire electromagnetic spectrum, including radio waves, ultraviolet, and X-rays, the dominant portion of their output falls in the infrared range, especially for cooler stars.