The+Sun's+photosphere+and+above



"__The Surface''__ the photosphere is a 500-kilometer-thick (300-miles-thick) Above the photosphere the tempature increases with altitude, reaching tempatures as high as 2 million degrees Celcius(3.5 million degrees Fahreheit)The surface area=6,087,799,000,00 km2 compared to 11,990 Earths.

The sun's photosphere

[|Sun Earth Day] Very cool site all about the sun. The Sun is a typical G2 star. G stars are classified as having a temperature in the range of 5000 to 6000 K, and a color ranging from white to yellow. Spectrally, G stars show most predominantly the lines of ionized calcium. Lines from ionized and neutral metals are present. Lines from ionized hydrogen show up weakly

What we see as the surface of the Sun, the photosphere, has a temperature of about 5780 K. The interior of the Sun probably has a temperature around 16 million K, and the extended outer atmosphere of the Sun, the solar corona, has a temperature around 2 million K. Between the photosphere and the corona is a layer called the chromosphere. It is in this region where most of the temperature rise from the surface to the corona takes place. The rapid heating from the surface of the Sun to the chromosphere and then of the corona, is one of the very interesting problems in solar physics. Especially since most of this change occurs in a distance of less than 200 km!

The diameter of the Sun is 1.4 million kilometers, and is about 150 million km away from the Earth. In contrast, the diameter of the Earth is 12735 km, about 1/100 the size of the Sun. The distance from the Earth to the Sun varies throughout the year. At perihelion (closest approach) the distance is 147 million km, and at aphelion (farthest) the distance is 152 million km. Due to this distance variation, the Sun will appear about 3% bigger at perihelion than at aphelion. At this point in geological time, perihelion occurs in early January, and aphelion in early July. Slowly but surely, however, the perihelion point precesses, so in 23,000 or so years, perihelion will occur in July. Note that the Earth's seasons are due to the inclination of the Earth's equator with respect to the Earth's orbital plane, which is about 23 degrees. The Earth-Sun distance variation has only an incredibly small effect in temperature. Here's a way you can test this. Put yourself about 152 feet away from a friend, and then have them yell at you. Then, move 5 feet (3%) closer, and have them yell again. You will notice almost no difference in how loud they sound. (The metric equivalent is: 46 meters away, and then 1.5 meters closer.) The Sun's age is estimated to be around 4.5 billion years. It should remain more or less as it is for another 5.5 billion years, although it will continually be undergoing changes as it consumes its fuel through fusion.