APOD 2.1 Blue Sun Bristling

This image of our sun was taken at the Hydrogen-Alpha wavelength of the spectrum. Hydrogen-Alpha's wavelength is 656 nm. The image was then inverted to appear blue. The sun is mostly composed of hot hydrogen gas. Taken at the Hydrogen-Alpha wavelength, the sun's chromosphere is easily visible. Spicules, thin long tubes about the length of the radius of the Earth that are composed of magnetically-confined hot gas, can also be seen bursting from the sun. Many people believe that the sun is on fire, but this is far from the truth. The sun has barely any Oxygen, which is essential to fire. In reality, the sun is just extremely hot gas. Energy from the sun is due to the fusion of hydrogen and helium in the core of the sun. Solar prominences can also be seen extending from the sun. Average size prominences extend many thousands of kilometers into space. However, in the picture they appear very tiny. This evidence shows how massive the sun really is. Sunspots, often visible on the sun, were not visible on the day that this photo was taken.