Astronomers detect radiation from stars across a wide range of the electromagnetic spectrum, not just visible light. Explain why different types of electromagnetic radiation from stars must be detected using telescopes in space rather than from the ground, and describe what the continuous spectrum of radiation from a star can tell astronomers about the star's properties.

Space‑based telescopes are required because the Earth's atmosphere absorbs many wavelengths of stellar radiation – for example, gamma rays, X‑rays, most ultraviolet and a substantial part of the infrared. As a result, ground‑based instruments cannot detect these photons and would miss the corresponding parts of the spectrum.

Because a space telescope is above the atmosphere, it can observe the full range of wavelengths that reach the star, including those that would otherwise be absorbed. This allows astronomers to collect the complete spectrum of a star.

The continuous spectrum of a star is a black‑body curve. The wavelength at which the spectrum peaks (the peak wavelength) is directly related to the star's surface temperature via Wien's law: a higher temperature shifts the peak to shorter wavelengths, i.e. towards the blue end of the spectrum.

The overall intensity of the continuous spectrum, when combined with the distance to the star, gives the star's luminosity – the total power output. Thus, by measuring the shape and brightness of the spectrum, astronomers can determine both the temperature and luminosity of the star.