The Very Latest SOHO Image of the Sun

This image shows the latest solar captured by NASA on February 22, 2008 at the real time of 19:19.

More solar images can be viewed from here. Other scientific solar resources can be obtained from here too.

Brief Introduction of the Sun

The core of the sun is said to have a density of up to 15000kg/m3. This density is 150 times higher than the density of the Earth. The thermonuclear reaction (nuclear fusion process)converts about 700,000,000 tones of hydrogen to about 695,000,000 tones of helium into the form of gamma rays every second and later the released energy of about 5,000,000 tones or equivalents to 3.86e33 ergs from the sun maintains it in a stable state. Every second, approximately 8.9 X 1037 Proton, which is a conversion of 426 tones hydrogen nuclei into helium nuclei. About 383 X 1024 joules of released energy within every second is equivalents to 9.15 X 1010 million tons of explosive energy of TNT.
From its core to its solar radii distance of 0.2, this is regarded as the only place for the sun to release its nuclear fusion energy. The remaining part of the sun is heated by such releasing energy that will later be transmitted and extended outwards to parts of the sun. This heating energy passes through many linked layers before reaching to its outer surface, and subsequently entering the space.

High-energy photons (γ and X-ray) are released from the core through the nuclear fusion process. Later, this energy has to take longer times to reach the outer surface of the sun. The slow pace and its changing path of its direction involve absorption and re-radiation of energy and thus causing relatively lower external photon energy. It is estimated that the time taken for each of the photon energy to reach its surface is 5000 million years, and the fastest was reported as 17,000 years. After venturing through the troposphere and finally reaching the end of its transparent ball-layer looking surface, the visible light photon escapes to the space.

Before entering the space, each γ-ray photon has already been converted into millions of visible light photons. Neutrino is another result of nuclear reactions that take place in the sun. It is different from the photon energy as it does not react with other substances and therefore it escapes immediately from the surface of the sun to the space. Over years, the number of measured neutrinos from the sun is always found lower than the theoretical value and thus creating the issue of neutrino for the scientists to venture into the depth study in this field. This mystery was then solved when scientists came to understand the theory of the neutrino’s oscillation.

Very close to the core of the sun, its temperature is about 15 million K and its density is approximately 1.5g/cc or equivalents to about 10 times of the density of lead. Nevertheless, its temperature becomes less when moving from the core to the sun’s surface, and its density too, reduces simultaneously. Its edge temperature is half of the core’s temperature, that is approximately 7 million K, and at the same time its density is about 20g /cc as equivalent as the density of gold.