Nearest star – At “just” 149,600,000 km (93,000,000 mi) from Earth, the Sun is considered astronomically close. The next nearest star, Proxima Centauri,
is 4.2 light years away, or 40,000,000,000,000 km (24,000,000,000,000 mi).
The pioneering work carried out by Father Angelo Secchi (ITA, 1818–78) in spectroscopy led to his classification scheme for stars, and to his conclusion that our own Sun was a star and not a phenomenon unique to the Solar System.
Gas: Like all stars, the Sun is a large ball of gas. Hydrogen accounts for more than 70% of its mass and helium 27%.
Diameter: At 864,000 mi (1,390,473 km) across, the Sun is around 109 times
larger than Earth.
Temperature: The heat at the Sun’s core is c. 27,000,000°F (15,000,000°C). At its surface, it is “just” 10,000°F (5,537°C).
Rotation: The Sun rotates faster at the equator (about 27 days) than it does at the poles (about 36 days).
The Sun has a mass around 333,0 0 0 times greater than that of Earth. This represents more than 9 9% of the mass of the entire Solar System, which is
held together and kept in orbit around the Sun by our star ’s immense gravity.
Find out more about Stars – HERE