Facts about the Sun's Photosphere

The portion of the sun we see is called the photosphere.
••• Siri Stafford/Lifesize/Getty Images

The surface of the sun, or photosphere, is a yellow-colored layer of thick, hot gases marked with dark spots, known as sunspots. It is the lowest visible layer of the sun.

Temperature

The photosphere is 5,780 degrees Kelvin (K), which is relatively cool compared to the inside, measured in the millions of degrees, and the atmospheric edge, which is also measured in the millions of degrees.

Opacity

The gases that make up the photosphere are completely opaque, meaning that you cannot see through them. Therefore, stating that the sun has “surface” is a misnomer, for the photosphere is not solid.

Location

The photosphere is above the solar convection zone, where heat from the core radiates outward and below the chromosphere, where heat is transferred to the outer layer of the sun, called the corona.

Composition

The photosphere is constructed of convection cells called granules, which are cells of hot gas 1,000 km in diameter. Each granule lives 8 to 9 minutes, which produces a “boiling” effect.

Sunspots

Sunspots are cooler regions of the photosphere that appear dark because of their lower temperatures of 3,800 degrees K versus 5,780 degrees K. Sunspots can vary in size up to 50,000 km in diameter.

Related Articles

The Outer & Inner Parts of the Sun
What Is the Average Temperature of Jupiter?
Three Major Characteristics of the Inner Planets
The Outer & Inner Parts of the Sun
Describe the Surface Terrain on Jupiter
What Is the Surface Terrain Like on Neptune?
How Thick or Thin Is the Earth's Atmosphere?
The Characteristics of Comets, Meteors & Asteroids
What Causes the Thermosphere to Be So Hot?
What Is the Earth's Atmosphere Composition & Temperature?
Facts About the Chromosphere of the Sun
What Are the Elements of Uranus?
How High Does the Atmosphere Extend From Earth?
Which Planets Are the Gas Planets?
How is the Sun Nuclear Energy?
What Are Some Interesting or Unique Features of Neptune?
How Does the Sun Release Energy?
What Are the Planets in Our Solar System Held in Their...
Characteristics of a Star
What Layer of the Atmosphere Is of the Greatest Interest...