Nothing But The Facts About The Sun

Human beings have long acknowledged the Sun's role in supporting life on Earth. Thus many civilizations throughout the past have worshiped the Sun. They have given it an important role in their religions and traditions

General facts about Sun:

1. Spectral Type of Star G2 V
2. Sun contains 98% of the total solar mass.
3. Age of the sun: 4.5 billion years (about 1.64 x 10^12 days).
4. Mass: 330,000 x Earth (it has 333,400 times more mass than the Earth)
5. Distance from Earth: 149.6 million km (93 million miles)
6. Nearest Star: Proxima Centauri (which is 4.3 light years far from sun)
7. Density: 1.41 g/cm3
8. Luminosity: 390 billion megawatts
9. Solar Wind Speed: Highest (800 km/s at coronal holes) Lowest (300km/s at streamers)
10. Solar Sunspot Cycle: 8 - 11 years
11. Solar corona: Sun's atmosphere
12. The Sun's outer visible layer: The photosphere
13. Temperature of photosphere: 6,000°C (11,000°F).
14. Temperature at the core: (15,000,000° C; 27,000,000° F)
15. Pressure at the core: (340 billion times Earth's air pressure at sea level)
16. Sunspots: Dark depressions on the photosphere
17. Temperature of Sun spots: 4,000°C (7,000°F) which is cooler than the surrounding surface (6000C)
18. Faculae: Bright luminous spots on the sun's surface associated with strong magnetic fields.
19. Flares: Bright filaments of hot gases that erupt when energy that is stored in twisted magnetic fields is suddenly released.
20. Prominences: Clouds of glowing gas that erupt from the surface and form arcs reaching into the corona.
21. Equatorial radius: 695,000 Kms
22. Rotation (Equator): 25 Earth days
23. Rotation (Poles): 35 Earth days
24. Composition: 71% Hydrogen [H],26.5% Helium [He],2.5% Other
25. Solar Constant : 1.37 KWatts / m^2
26. Coronal Mass Ejections: Ejections in which material comes out from the region of solar corona which can be observed through white-light coronagraph.

Few amazing facts about sun

1. 585BC: Sun's first solar eclipse was recorded.

2. 11 years cycle of sun is now close to a solar maximum (in 2012), a period discernible by frequent sunspots and flares.

3. The aurora borealis in the north, or aurora australis in the south is caused by the influx of particles from the sun due to solar flares and CME, interacting with Earth's magnetic field.

4. Magnetic flip of Sun's Magnetic field: In February 2001 it was published in NASA report that Sun's magnetic field had flipped. Sun's North Pole, which had been in the northern hemisphere of the Sun before the flip, shifted to the southern hemisphere. The flip happens at the peak of each solar cycle (the last in the year 2000).

Photo Credits:

Photo #1 http://eclipse99.nasa.gov/pages/SunActiv.html

Photo #2 http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/sun_image.html

Photo #3 http://www.nasa.gov/vision/universe/solarsystem/solar_live.html

References:

1) Magnetic Flip of earth:http://www.spacetoday.org/SolSys/Sun/Sunspots.html

2) History of Solar eclipses: http://www.bibalex.org/eclipse2006/HistoricalObservationsofSolarEclipses.htm

3) Solar Maxima: http://en.wikipedia.org/wiki/Solar_maximum