The Sun, our nearest star, is a gigantic ball of hot, glowing gas. Here are some of its key physical properties:
Size and Mass:
* Radius: 695,000 km (432,000 miles) – about 109 times the Earth's radius
* Diameter: 1.39 million km (865,000 miles)
* Mass: 1.989 × 10^30 kg (4.385 × 10^30 lbs) – about 333,000 times the Earth's mass
Composition:
* Hydrogen: ~70.6% by mass
* Helium: ~27.4% by mass
* Other elements (oxygen, carbon, neon, iron, etc.): ~2% by mass
Temperature:
* Core: 15 million degrees Celsius (27 million degrees Fahrenheit)
* Surface (photosphere): 5,500 degrees Celsius (9,932 degrees Fahrenheit)
* Corona (outermost layer): 1 million to 3 million degrees Celsius (1.8 million to 5.4 million degrees Fahrenheit)
Luminosity:
* Total: 3.846 × 10^26 watts
* Apparent magnitude: -26.74 (this is the brightness as seen from Earth)
Rotation:
* Equatorial: 25.05 days
* Polar: 36 days (the Sun rotates differentially, meaning its rotation speed varies with latitude)
Magnetic field:
* Strength: Varies significantly, but can be very strong in active regions
* Structure: Complex and dynamic, with constantly evolving sunspots and other features
Other notable properties:
* Gravity: 274 m/s² (27.9 times Earth's gravity)
* Density: 1.41 g/cm³ (about 1.4 times the density of water)
* Age: Approximately 4.6 billion years old
* Lifetime: Estimated to be another 5 billion years
Important Note: These are just some of the key properties of the Sun. There is still much we don't know about our star, and ongoing research continues to reveal new insights about its structure, behavior, and influence on our solar system.
