Which wavelength of radiation do astronomers use to find the hottest stars?

Astronomer use ultraviolet (UV) radiation to find the hottest stars. UV radiation is a type of electromagnetic radiation with a wavelength shorter than visible light but longer than X-ray radiation. The hottest stars emit a significant amount of UV radiation because their surface temperatures are extremely high. By observing the UV radiation emitted by stars, astronomers can estimate their temperatures and identify the hottest ones.