The image of the SUN perpendicular to center of its circumference.

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Sun/Earth Comparison

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Bulk parameters

                                     Sun          Earth      Ratio (Sun/Earth)
Mass (1024 kg)                     1,988,500.      5.9726      333,000.    
GM (x 106 km3/s2)                    132,712.      0.3986      333,000.  
Volume (1012 km3)                  1,412,000.      1.083     1,304,000. 
Volumetric mean radius (km)         696,000.       6371.      109.2
Mean density (kg/m3)                1408.          5514.        0.255       
Surface gravity (eq.) (m/s2)         274.0         9.78        28.0     
Escape velocity (km/s)               617.6        11.19        55.2     
Ellipticity                         0.00005        0.0034       0.015
Moment of inertia (I/MR2)              0.059       0.3308       0.178      
Visual magnitude V(1,0)              -26.74       -3.86          -  
Absolute magnitude                    +4.83
Luminosity (1024 J/s)                384.6
Mass conversion rate (106 kg/s)     4300.         
Mean energy production (10-3 J/kg)     0.1937
Surface emission (106 J/m2s)          63.29
Spectral type                         G2 V

Model values at center of Sun:
Central pressure:     2.477 x 1011 bar                 
Central temperature:  1.571 x 107 K
Central density:      1.622 x 105 kg/m3

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Rotational and Orbital parameters

                                          Sun        Earth      Ratio (Sun/Earth)
Sidereal rotation period (hrs)*         609.12       23.9345     25.449     
Obliquity to ecliptic (deg.)              7.25       23.45        0.309
Speed relative to nearby stars (km/s)    19.4

*This is the adopted period at 16 deg. latitude – the actual rotation rate varies with latitude L as:

( 14.37 – 2.33 sin² L – 1.56 sin⁴ L ) deg/day

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North Pole of Rotation

Right Ascension: 286.13
Declination    :  63.87
Reference Date : 1.5 Jan 2000 (JD 2451545.0)

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Sun Observational Parameters

Apparent diameter from Earth
        At 1 A.U.(seconds of arc)  1919.
        Maximum (seconds of arc)   1952.
        Minimum (seconds of arc)   1887.
Distance from Earth
        Mean (106 km)              149.6
        Minimum (106 km)           147.1
        Maximum (106 km)           152.1

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Solar Magnetic Field

Typical magnetic field strengths for various parts of the Sun 

Polar Field:  1 - 2 Gauss 
Sunspots:  3000 Gauss
Prominences:  10 - 100 Gauss
Chromospheric plages:  200 Gauss
Bright chromospheric network:  25 Gauss
Ephemeral (unipolar) active regions:  20 Gauss

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Solar Atmosphere

Surface Gas Pressure (top of photosphere): 0.868 mb 
Pressure at bottom of photosphere (optical depth = 1): 125 mb
Effective temperature: 5778 K
Temperature at top of photosphere:  4400 K
Temperature at bottom of photosphere:  6600 K
Temperature at top of chromosphere:  ~30,000 K
Photosphere thickness:  ~500 km
Chromosphere thickness:  ~2500 km
Sun Spot Cycle:  11.4 yr.

Photosphere Composition: 
    Major elements: H - 90.965%, He - 8.889%
    Minor elements (ppm): O - 774, C - 330, Ne - 112, N - 102
			  Fe - 43, Mg - 35, Si - 32, S - 15

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