Reddening

Definition

Reddening is the process in which light from stars or other celestial objects appears redder than it actually is due to scattering by interstellar dust. This effect occurs because shorter wavelengths of light (blue) are scattered more than longer wavelengths (red).

5 Must Know Facts For Your Next Test

1. Reddening is caused primarily by interstellar dust grains that scatter and absorb light.
2. This phenomenon can affect astronomical observations, making stars appear cooler and farther away than they are.
3. The amount of reddening is quantified using the color excess, denoted as E(B-V).
4. Reddening does not change the intrinsic luminosity of a star but alters its observed color and brightness.
5. Astronomers use models of reddening to correct their observations and better understand the properties of celestial objects.

Review Questions

• What causes the reddening effect observed in starlight?
• How does reddening affect our perception of a star's distance and temperature?
• What is the color excess, and how is it related to reddening?

Related terms

Interstellar Dust: Tiny particles in space composed of elements like carbon, silicon, and oxygen that cause scattering and absorption of light.

Extinction: The combined effect of absorption and scattering by interstellar dust that dims the light from celestial objects.

Color Excess (E(B-V)): A measure used to quantify the amount of reddening experienced by starlight passing through interstellar dust.