The centre of the solar system around which all the planets, moons, comets and asteroids orbit, the Sun's heat and light are essential for life.
Explore facts about the biggest and hottest object in the solar system.
The Sun facts
- Equator circumference: 4,379,000km
- Radius: 695,700km
- Temperature: 5,973°C to 15,000,000°C
- Average orbital speed around the Milky Way: 720,000km/h (200km/s)
- Star type: Yellow dwarf
- Average time taken to rotate on axis: 27 Earth days
- Number of planets: 8
How big is the Sun?
The Sun is the biggest object in our solar system, with a distance of 695,508
The Sun is an average-sized star. Some stars are just a tenth of its size, while others are more than 700 times bigger. Due to its huge mass and strong gravity, the Sun is a
How hot is the Sun?
The core is the hottest part of the Sun, at 15 million degrees Celsius. This is hot enough to sustain thermonuclear
The energy produced at the core takes up to a million years to reach the outer layer known as the convective zone. At this
In the Sun's atmosphere, known as the corona, the temperature begins to rise again to roughly two million degrees Celsius. As
What is the Sun made of?
The Sun is a ball of gas and plasma - around 91% of it is hydrogen gas. Under intense heat and gravitational
When the plasma is heated to the temperatures seen on the Sun, it contains so much energy that the charged particles can escape the star's gravity and blow out into space. This is called solar wind - under certain conditions, when it hits Earth's atmosphere it can cause auroras, such as the Northern Lights.
In addition to hydrogen and helium, scientists have detected at least 65 other elements in the Sun. The most abundant of these include oxygen, carbon, nitrogen, silicon, magnesium, neon, iron, and
Does the Sun rotate?
Yes. Even though the Sun is not solid like Earth, it still has a rotation as the plasma swirls around its surface. On average, it takes 27 Earth days for the Sun to rotate once on its axis, but different parts move at different speeds. The equatorial regions take just 24 days to rotate and the polar regions more than 30.
What are sunspots?
Sunspots are cooler parts of the Sun's
These cooler spots can be up to 50,000
What are solar flares?
Solar flares are the largest explosive events in the entire solar system. They occur when the magnetic fields associated with the sunspots convert energy into heat and accelerating particles, ejecting it into space.
What type of star is the Sun?
The Sun is currently a yellow dwarf. Like all stars, it began as a contracting nebula - effectively a cloud of dust and gas.
As each particle has its own tiny gravitational pull, the dust and gas began to coalesce into a protostar. As this mass is pulled together and collapses in on itself it generates heat. If it becomes big enough it will eventually get sufficiently hot to fuse hydrogen into helium. This was how the Sun formed.
The celestial object then enters its main sequence stage, during which the outward pressure of nuclear fusion is balanced by the inward pressure of the stars own gravity. The Sun is currently in this stable phase.
When will the Sun explode?
It won't. When all of the hydrogen in its core is burned up, it exits the main sequence stage.
As a relatively small star, the outer layers of the Sun will collapse in on themselves, creating temperatures hot enough to fuse helium into carbon. At this
For the Sun, this is expected to occur in about five billion years. It is likely to engulf Mercury and Venus - and potentially even the Earth.
It will eventually shrink to become a planetary nebula with a white dwarf at its core.
Where is the Sun in the Milky Way?
There are an estimated 100 billion galaxies in the known universe. The Sun and its eight planets, including Earth, reside in one known as the Milky Way. Our galaxy is around one quintillion
The Sun is in a spiral arm of the Milky Way called the Orion Spur. This branches off from the galaxy's Sagittarius arm. The Sun and our solar system are orbiting around the
What is a solar eclipse?
Sometimes the Moon comes between the Sun and Earth. If all three are aligned, the Moon can block the Sun entirely, casting a shadow on Earth and causing a solar eclipse. This is because even though the Sun is 400 times larger than the Moon, the Moon is 400 times closer to Earth.
Solar eclipses occur roughly every six months, but total solar eclipses, in which the Sun is completely obscured by the Moon, are much rarer. They tend to occur around every two years, although often in remote areas of the Earth. These total eclipses can last for as little as a few seconds, but never longer than seven minutes.
How do we study the Sun?
Due to its extreme temperatures studying the Sun with
However, in 2019 the European Space Agency and NASA will launch the Solar Orbiter, which will enter an elliptical orbit of the Sun allowing unprecedented observations.
After taking three and a half years to reach the Sun, it will begin a