Photosphere

Definition

The photosphere is the visible surface layer of the Sun from which light is emitted. It is typically about 500 kilometers thick and has an effective temperature of around 5,800 Kelvin.

5 Must Know Facts For Your Next Test

1. The photosphere is where most of the Sun's visible light originates.
2. It has a grainy appearance due to granulation caused by convective currents of plasma.
3. Sunspots, which are cooler and darker regions, can be observed on the photosphere.
4. The photosphere's temperature varies from about 4,500 K in sunspots to around 6,000 K in brighter areas.
5. It plays a crucial role in solar observation and helps astronomers understand solar dynamics.

Review Questions

• What is the primary function of the photosphere?
• How does granulation occur on the photosphere?
• Why do sunspots appear darker than their surroundings on the photosphere?

Related terms

Chromosphere:

A thin layer above the photosphere characterized by a reddish glow as seen during solar eclipses.

Corona:

The outermost part of the Sun's atmosphere, extending millions of kilometers into space and visible during a total solar eclipse.

Sunspot: A temporary phenomenon on the photosphere appearing as spots darker than surrounding areas due to lower temperatures.