Astronomy Flashcards: The Sun

Sun Structure and Composition

• The Sun is composed entirely of hot gas.
• Hydrogen is the most abundant element in the Sun.
• The core extends from the center to about 0.2 to 0.25 solar radii, reaching temperatures of 15 million Kelvin and densities of 150 g/cm³.

Solar Atmosphere

• The Sun's atmosphere consists of three main layers: photosphere, chromosphere, and corona.
• The photosphere is the layer from which visible light escapes; it is approximately 500 km deep with a temperature of about 5800 K.
• The chromosphere is located between the photosphere and the corona, roughly 3,000 to 5,000 kilometers deep, and appears rosy red during eclipses.

Solar Wind and Magnetic Interactions

• Approximately ten million tons of particles escape the Sun yearly as solar wind, primarily through regions known as coronal holes.
• Solar wind particles are captured by Earth’s magnetosphere, causing aurorae (northern and southern lights) when they spiral into the atmosphere.

Solar Features and Phenomena

• Granulation refers to the fine structure of bright grains on the Sun's surface, indicating hot material rising from the interior.
• Sunspots are cooler areas on the Sun's surface, typically reaching about 3800 K, compared to the surrounding photosphere at about 5800 K.
• A solar flare is a sudden flash of increased brightness on the Sun, often near a sunspot group.

Energy Transport Mechanisms

• Energy moves inward and outward within the Sun through three mechanisms: conduction, convection, and radiation.
• The radiation zone transports energy primarily through radiative diffusion and thermal conduction, while the convection zone allows energy to be transported by convection.

Misconceptions

• Coronal holes are not uniformly shaped; they constantly change and reshape due to the dynamic nature of the corona.
• It is false to state that solar flares are not connected with sudden changes in the Sun’s magnetic field.

Prominences

• A prominence is a large, bright, gaseous feature that extends outward from the Sun's surface, typically in a loop shape.

Test your knowledge on the structure and characteristics of the Sun with these astronomy flashcards. Explore key concepts such as the photosphere and solar wind. Perfect for students and enthusiasts of astronomy.