The present study, led by Tanmoy Samanta and Hui Tian of Peking University, China, has deciphered how these spicules form and also shows that they act as conduits through which hot plasma is carried into the corona region. It has been suspected that these spicules act as conduits through which mass and energy from the lower atmosphere bypass the photosphere and reach the corona. While in a photograph these look like tiny hairlike projections, they are in fact 200-500 kilometres wide and shoot up to heights of about 5,000 km above the solar surface. The key to the puzzle lies in geyser-like jets known as solar spicules that emanate from the interface of the corona and the photosphere. Science, the team of solar physicists has made observations and matched it with an analysis that explains this conundrum. The puzzle of coronal heating has been tackled by many theories.

This implies there should be a source heating the corona. However, with respect to the Sun, after dropping to a low, the temperature again rises to one million degrees in the corona which stretches over several million kilometres from the surface of the Sun. One would expect that as there are no extra sources of heat, when you move away from a hot object, the temperature steadily decreases. It starts increasing outside the photosphere, reaching a value of about one million degrees or more in the corona. However, the temperature of the corona is much higher. The natural thing to expect is that still further outwards, in its atmosphere, known as the corona, the temperatures would be comparable to that at the surface (photosphere).

The temperature at the core of the Sun is nearly 15 million degrees Celsius, while that at its surface layer, known as the photosphere, is merely 5,700 degrees C. These observations may have unravelled why the SunвЂ™s atmosphere is hotter than its surface. An international team of researchers including one at Indian Institute of Astrophysics, Bengaluru, has had a go at this question. One of the puzzles concerns its surface and atmospheric temperature. Yet, it harbours many a puzzle for the solar physicist. The Sun is one of the most familiar celestial objects вЂ“ it is on the sky everyday.

Sun corona temperature in celsius