The central body of our Solar System, the sun is a yellow dwarf star born out hydrogen triggered nuclear fusion which took place about 4.6 billion years ago. Though in astronomical terms the sun is not considered to be a large star but it is still the largest body within our Solar System containing about 99% of the matter of the system. Besides it also controls the orbital path of other celestial bodies within the system.
The sun is the main source of heat providing enough warmth to enable at least one planet produce life forms. The temperature at the core is about 20 million degrees Centigrade. Energy is radiated from sun in form of radio waves, microwaves, infrared radiation, visible light spectrum, ultra violet radiation, x-rays & gamma rays. The equatorial region rotates once every 27.275 days while its Polar Regions rotate every 34 days. In absence of any molecular solid the sun is a gaseous sphere without any solid surface. The surface consists of granular sea of gaseous firestorms known as photosphere. These are roughly 600 miles in diameter. Due to presence of negative hydrocarbon these granules are partly opaque and during the eight-minute life span hot gas rush out of the center pushing the cooler ones outside. Sometimes violent surface eruptions explode from the photosphere. The energy from such eruption equals ten million hydrogen bombs. These are called Solar Flares.
First observed in 1859 by Richard Carrington, solar flares take several hours or days to build up but are released within minutes. Solar flares range one per Earth week to several flares per Earth day. The period when the frequency of flares is low is called the quite period. The resultant shock waves travel outwards for hundreds of thousands of miles. It is believed that the magnetic energy of the sun causes such flares. The charged particles released in the flares are attracted by the Earth's magnetic field causing the Aurora Borealis in Earth's atmosphere. The dark & cooler regions on the surface of the photosphere are called Sunspots. During the quite period the sunspots are hardly seen, but hundreds are observed clearly during the active period. Sunspots vary in shape & size. They usually occur in groups. They grow to their full size within a week but take over two weeks to decay. A thin transparent layer called chromosphere covers the photosphere. Surrounding the chromosphere is the vast field of hydrogen particles called the corona. The corona is not visible against the bright sun and can be observed only during a total solar eclipse. Blowing outwards from the sun is the stream of hot, ionized, subatomic particulate plasma called solar wind. In some cases these solar winds form into a fireball known as coronal mass ejection better known as giant maelstrom of ionized gases at temperature over a million degree. Such plasma can tear into the earth's magnetic field causing potential negative effect on spacecraft, frying the electronic components of the telecommunication satellites, and knocking out power supplies even put millions of cell phones and other wireless devices through out the globe out of action. It can smash through the skin of the spacecraft and lodge inside dielectric materials like thermal blankets, electronic boards, coaxial cables, and electric insulation. It can create a strong electric field inside the spacecraft. Scientists have been observing the sun since the past 200 years and have observed several the occurrence of such fireballs every eleven years.
The last such storm had struck North America during the early hours of March 13, 1989. A giant fireball of plasma had escaped from the sun four days ago hitting the earth & rapidly changing the magnetic field, caused the several power supply systems to collapse. At New Jersey the power station burnt out. At Quebec, Canada, the temperature dropped to 15 degrees C while the entire town went without power supply. The Oak Ridge National Laboratory in Tennessee has predicted that the next such geomagnetic storm will be slightly more severe and would cost the U.S. economy up to $ 6 billion. Astronomers are counting the number of sunspots and the number of groups of sunspots during fixed intervals. These numbers determine the International Sunspot Number. During the minimum, the sunspot number cans be as low as 10. In July 1989 during the last solar maximum the peat was 159. The highest was 201 in March 1958. Panels of experts warn that the sunspot number could reach 190 between June 1999 & January 2000. A group of worried scientists are working round the clock in developing a complex computer to predict which parts of the earth might be affected. The club will be carrying our sunspot observation for members during May-June this year.
Amateur astronomers round the world have already started carrying out observation of the sun spots. The 11th August Solar Eclipse was considered the best time to carry out such observation. Several astronomers in Europe, Asia including India carried out special test and observations. The period during the totality was be the best time to photograph the sun to catch any solar activity buildup especially any sun flares.
