The Sun (also called Sol) is the star at the center of our solar system.
It is the primary source of energy for Earth, driving our climate, weather, and the conditions that make life possible. The Sun is an almost perfect sphere, with a difference of only about 10 km between its polar and equatorial diameters. Its average radius is approximately 695,508 km, making it about 109 times wider than Earth. Roughly 20–25% of this radius is occupied by the Sun’s core, where nuclear fusion takes place.
| Age: | 4.6 Billion Years |
| Type: | Yellow Dwarf (G2V) |
| Diameter: | 1,392,684 km |
| Equatorial Circumference | 4,370,005.6 km |
| Mass: | 1.99 × 10^30 kg (333,060 Earths) |
| Surface Temperature: | 5,500 °C |
Star Profile | |
|---|---|
Age | 4.6 Billion Years |
Equatorlal Diameter | 1,392,700 km |
Polar Diameter | 1,392,700 km
(The Sun is nearly perfectly spherical) |
Mass | 1.99 × 10³⁰ kg
(≈ 333,000 Earths) |
Moons | 0 |
Orbit Distance | 0 km
(All planets orbit the Sun) |
Orbit Period | Orbits the Milky Way’s center (every ~225–250 million years.) |
Surfface Tempature | ≈ 5,500 °C
(Core temperature ≈ 15 million °C) |
Rotation Period | ≈ 25 days (equator)
≈ 35 days (poles) |
Atmosphere | Hydrogen and helium
(Photosphere, chromosphere, corona) |
Surface Gravity | 274 m/s²
(≈ 28× Earth) |
Energy Source | Nuclear fusion
(Hydrogen → helium) |
First Record | Prehistoric |
Recorded By | Ancient civilizations worldwide |
At its core, the Sun reaches temperatures of about 15 million °C.
Although it appears yellow from Earth, the Sun emits light across the entire visible spectrum and is effectively white in color. It is composed primarily of hydrogen (about 70%) and helium (around 28%), with trace amounts of heavier elements.
The Sun is classified as a G2V main-sequence star, often referred to as a yellow dwarf. It formed approximately 4.6 billion years ago and has enough nuclear fuel to shine for several billion more years. The Sun is about 109 times wider than Earth and approximately 330,000 times more massive, dominating the mass of the solar system.
If Earths were packed tightly with no empty space, about 1.3 million could fit inside the Sun. With natural gaps between spheres, around 960,000 Earths would fit. The Sun’s surface area is nearly 12,000 times greater than Earth’s.
About 99.86% of the solar system’s mass is contained within the Sun. It is roughly 330,000 times more massive than Earth and is composed mostly of hydrogen, with most of the remainder being helium.
There is only about a 10 km difference between its polar and equatorial diameters. Given its immense size, this makes the Sun one of the most spherical natural objects ever observed.
Temperatures at the Sun’s core reach about 15 million °C, where nuclear fusion converts hydrogen into helium. The Sun’s immense gravity prevents it from expanding explosively. At the surface, temperatures are closer to 5,600 °C.
When the Sun exhausts its hydrogen fuel, it will expand into a red giant, likely consuming Mercury, Venus, and Earth. This phase will last millions of years before the Sun sheds its outer layers.
After its red giant phase, the Sun will collapse into a white dwarf, retaining much of its mass but compressed into a volume similar to Earth’s.
Light travels from the Sun to Earth in about 8 minutes and 20 seconds. However, the energy itself may take millions of years to move from the Sun’s core to its surface.
The Sun travels at about 220 km per second and takes roughly 225–250 million years to complete one orbit around the center of the Milky Way.
Because Earth follows an elliptical orbit, the distance varies from 147 to 152 million km throughout the year. This average distance is called one Astronomical Unit (AU).
At around 4.6 billion years old, the Sun has burned roughly half of its hydrogen fuel. It has enough remaining to continue shining for another 5 billion years. It is currently classified as a yellow dwarf star.
Solar flares and sunspots occur when magnetic energy is released during solar storms. In sunspots, magnetic field lines twist and rotate, similar to tornadoes on Earth.
A constant stream of charged particles flows outward from the Sun at speeds of about 450 km per second, shaping space weather throughout the solar system.
