Sun
The Sun is the star at the center of the Solar System and the dominant source of light and heat for Earth.
The Sun is the star at the center of the Solar System and the dominant source of light and heat for Earth.
What it is
The Sun is a sphere of hot plasma, mostly hydrogen and helium, classified as a G-type main-sequence star (G2 V). It is about 4.6 billion years old and contains more than 99% of the Solar System’s mass. Its visible surface is called the photosphere, and its atmosphere includes the chromosphere and corona.
Why it matters
The Sun provides the light and heat that make life on Earth possible. It drives weather, climate, ocean currents, and photosynthesis. For Canada, the Sun directly influences seasonal daylight variation, climate patterns, and the growing potential of solar energy across the country.
Key details
The Sun’s core reaches about 15 million K, where nuclear fusion converts hydrogen into helium, releasing energy as light and heat. Its diameter is roughly 1,392,000 km, and its surface temperature is about 5,780 K. The Sun dominates the Solar System gravitationally and has been studied since antiquity.
In short
- The Sun is a G-type main-sequence star, about 4.6 billion years old.
- It produces energy through nuclear fusion in its core.
- It contains more than 99% of the Solar System’s mass.
- It is essential for life on Earth and influences Canadian climate and seasons.
The Sun is directly relevant to Canadian climate, seasons, daylight variation, solar energy, and space science education across Canada.
Quick questions
What is the Sun?
How does the Sun produce energy?
Why is the Sun important for Earth?
Sources
- Britannica — Supports: Defines the Sun as the star around which Earth and the other solar system bodies revolve, and notes its dominant mass and role as a source of energy.
- Britannica — Supports: Provides age, mass, diameter, temperature, spectral type, and rotation details for the Sun.
- National Geographic Society — Supports: Describes the Sun’s influence on weather, ocean currents, seasons, climate, and photosynthesis, and lists its major layers.
- Natural History Museum — Supports: Gives key facts including the Sun’s radius, temperature, mass share of the Solar System, star type, and composition.