All about SUN

1. All about SUN Floriene Marie M. Delimos (Jou11)

2. Characteristics • It is a star in the center of the Solar System. • It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. • It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass (about 2×1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System.

3. Characteristics Chemically, about three quarters of the Sun's mass consists of hydrogen, while the rest is mostly helium. The remainder (1.69%, which nonetheless equals 5,628 times the mass of Earth) consists of heavier elements, including oxygen, carbon, neon and iron, among others.

4. Composition

5. 1. Core2. Radiative zone3. Convective zone4. Photosphere5. Chromosphere6. Corona 7. Sunspot8. Granules9. Prominence

8. Transition Region

9. The Sun is a G-type main sequence star comprising about 99.86% of the total mass of the Solar System. It is a near-perfect sphere, with an oblateness estimated at about 9 millionths,which means that its polar diameter differs from its equatorial diameter by only 10 km. As the Sun consists of a plasma and is not solid, it rotates faster at its equator than at its poles. This behavior is known as differential rotation, and is caused by convection in the Sun and the movement of mass, due to steep temperature gradients from the core outwards..

10. The period of this actual rotation is approximately 25.6 days at the equator and 33.5 days at the poles. However, due to our constantly changing vantage point from the Earth as it orbits the Sun, the apparent rotation of the star at its equator is about 28 days. The centrifugal effect of this slow rotation is 18 million times weaker than the surface gravity at the Sun's equator. The tidal effect of the planets is even weaker, and does not significantly affect the shape of the Sun.

11. The power production by fusion in the core varies with distance from the solar center. At the center of the Sun, a power production density that more nearly approximates reptile metabolism than a thermonuclear bomb. Peak power production in the Sun has been compared to the volumetric heats generated in an active compost heap. The tremendous power output of the it is not due to its high power per volume, but instead due to its large size.

12. The fusion rate in the core is in a self-correcting equilibrium: a slightly higher rate of fusion would cause the core to heat up more and expand slightly against the weight of the outer layers, reducing the fusion rate and correcting the perturbation; and a slightly lower rate would cause the core to cool and shrink slightly, increasing the fusion rate and again reverting it to its present level.

13. SUN~The English proper noun sun developed from Old Englishsunne and may be related to south. ~Cognates to English sun appear in other Germanic languages, including Old Frisiansunne, sonne ("sun"), Old Saxonsunna, Middle Dutchsonne, modern Dutchzon, Old High Germansunna, modern GermanSonne, Old Norsesunna, and Gothicsunnō. All Germanic terms for the Sun stem from Proto-Germanic *sunnōn.

14. The SunObservation dataMean distancefrom Earth1.496×108 km8 min 19 s at light speedVisual brightness (V)−26.74 Absolute magnitude4.83 Spectral classificationG2VMetallicityZ = 0.0122Angular size31.6′ – 32.7′ Adjectivessolar

15. OrbitalcharacteristicsMeandistancefromMilky Waycore~2.5×1017km26,000light-yearsGalacticperiod(2.25–2.50)×108aVelocity~220km/s(orbitaroundthecenteroftheGalaxy)~20 km/s (relative to average velocity of other stars in stellar neighborhood)~370 km/s (relative to the cosmic microwave background)

16. Physical characteristicsMean diameter1.392×106 km 109 × EarthEquatorialradius6.955×105 km • 109 × EarthEquatorial circumference4.379×106 km 109 × EarthFlattening9×10−6Surface area6.0877×1012 km211,990 × EarthVolume1.412×1018 km31,300,000 × EarthMass1.9891×1030 kg333,000 × EarthAverage density1.408×103 kg/m3DensityCenter (model): 1.622×105 kg/m3Lower photosphere: 2×10−4 kg/m3Lower chromosphere: 5×10−6 kg/m3Corona (avg.): 1×10−12 kg/m3Equatorial surface gravity274.0 m/s227.94 g28 × EarthEscape velocity(from the surface)617.7 km/s 55 × EarthTemperatureCenter (modeled): ~1.57×107 K Photosphere (effective): 5,778 KCorona: ~5×106 KLuminosity (Lsol)3.846×1026W~3.75×1028lm~98 lm/W efficacyIntensity (Isol)2.009×107 W·m−2·sr−1

17. Rotation characteristicsObliquity7.25° (to the ecliptic)67.23°(to the galactic plane)Right ascensionof North pole286.13°19h 4min 30sDeclinationof North pole+63.87°63°52' NorthSidereal rotation period(at equator)25.05 days (at 16° latitude)25.38 days 25d 9h 7min 12s (at poles)34.4 days Rotation velocity(at equator)7.189×103 km/h

18. Photosphericcomposition (by mass)Hydrogen73.46%Helium24.85%Oxygen0.77%Carbon0.29%Iron0.16%Neon0.12%Nitrogen0.09%Silicon0.07%Magnesium0.05%Sulfur0.04%

19. The parts of the Sun above the photosphere are referred to collectively as the solar atmosphere.They can be viewed with telescopes operating across the electromagnetic spectrum, from radio through visible light to gamma rays, and comprise five principal zones: the temperature minimum, the chromosphere, the transition region, the corona, and the heliosphere.Theheliosphere, which Solar Eclipse may be considered the tenuous outer atmosphere of the Sun, extends outward past the orbit of Plutoto the heliopause, where it forms a sharp shock frontboundary with the interstellar medium. The chromosphere, transition region, and corona are much hotter than the surface of the Sun. The reason has not been conclusively proven; evidence suggests thatAlfvén wavesmay have enough energy to heat the corona.

21. Life Span

22. Summary • Sun is the star at the center of the Solar System. • The Sun is a G-type main sequence star comprising about 99.86% of the total mass of the Solar System. • The core of the Sun is considered to extend from the center to about 20–25% of the solar radius.

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