Its probably surprising to learn that the Sun is just a normal star. It only seems more significant because we are so close to it, at an average distance of 150 million km. As stars go, its not particularly big, nor small neither is it particularly bright nor faint. In fact it really is pretty average. All stars, the Sun included, live and die and its estimated that the Sun formed about 5 billion years ago out of a vast cloud of hydrogen gas and dust called a nebula. Since then, nuclear reactions have been going on deep in its core smashing hydrogen atoms together to form helium atoms and in doing so, producing a tiny amount of heat and light. Its this process which gives us the crucial heat and light we need to survive. Fortunately, there is enough material in the Sun for it to remain relatively stable for the next 5 billion years.
When studied with specialist equipment, the Sun is revealed in its true nature as a vast seething ball of gas with eruptions blasting out of the Surface. Studying it in normal ‘white’ light reveals strange spots on the surface, these are called sunspots and are magnetic disturbances in the gas, often dwarfing the Earth. They can be studied over months and years and patterns can be seen, for example the well understood 11 yearly sunspot cycle.
The visible surface of the Sun which sunspots can be seen on is called the photosphere and its surround by the chromosphere where all the eruptions called prominences and flares occur. This is in turn surrounded by the rather more difficult to study Corona. Typically this is only visible with professional equipment or during solar eclipses.
One very key and important point to remember with the Sun is NEVER to observe it directly either with optical aid or without. It can and will cause blindness. You can find details of how to safely observe the Sun in my tip below.
Its hard to appreciate the full enormity of the Sun as it lies so far from us, however its so large that you could fit just over 1 million planet Earth’s inside! With all the activity on the Sun, its no surprise that this giant object sometimes has a big impact on us here on Earth. The prominences and flares are examples of the way the Sun throws of material into the solar system. On occasions the material gets to us here on Earth and when it does, it can knock out communications satellites and other technology yet give rise to the amazing and beautiful aurora displays which can be seen toward the Poles on most nights but on rare occasions, further away.
Mark’s Observing Tip
The easiest and safest way to observe the Sun is to project an image of it through binoculars or a telescope. Point them at the Sun WITHOUT looking through (you can get lined up by looking at the shadow on the ground, when its at its smallest its pointing at the Sun), then place a piece of white card about 30 cm away from the eyepiece and you will see a projected image of the Sun on the card. Don’t place the card too close or leave the binoculars or telescope pointing at the Sun for too long.
DON’T leave the telescope or binoculars pointing at the Sun for more than a few minutes as the intense heat can cause the glue and plastic parts inside to melt and if you have a finder telescope, make sure you keep it covered up so that you do not inadvertently allow sunlight into it. If you have a telescope larger than 10 cm then you should make a cardboard mask with a hole cut into it about 7 cm or 10 cm and place it over the front end of the telescope to cut down the amount of light that enters.