Ultraviolet

Definition

Ultraviolet (UV) radiation is a type of electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. It plays a significant role in astronomical observations and has various effects on celestial bodies.

5 Must Know Facts For Your Next Test

1. Ultraviolet radiation is divided into three types: UVA, UVB, and UVC, each with different wavelength ranges and effects.
2. The Earth's atmosphere absorbs most of the Sun's ultraviolet radiation, particularly UVC and the majority of UVB.
3. UV radiation can ionize atoms and molecules, making it an essential tool for studying the composition of interstellar medium and star-forming regions.
4. Astronomical instruments like the Hubble Space Telescope are equipped with UV detectors to observe phenomena that are invisible in other wavelengths.
5. Ultraviolet astronomy can reveal information about hot stars, quasars, and the behavior of galaxies.

Review Questions

• What are the three types of ultraviolet radiation, and how do they differ?
• Why is most ultraviolet radiation from the Sun absorbed by Earth’s atmosphere?
• How does ultraviolet radiation aid in the study of interstellar medium?

Related terms

Electromagnetic Spectrum:

The range of all types of electromagnetic radiation stretching from radio waves to gamma rays.

Hubble Space Telescope:

A space telescope launched by NASA that observes in multiple wavelengths including ultraviolet.

Ionization:

The process by which an atom or molecule acquires a positive or negative charge by gaining or losing electrons.