the sun
The Sun resembles a golden disc and is worshipped by many. It is a huge mass that is constantly on the move, changing, wild, boiling ball of fire and heat. Even though the Sun is extremely hot, it's heat doesn't reach all of the planets in our milky-way galaxy. Our Earth is actually called the 'Goldilocks' planet as it is located in just the right place in the solar system. This particular area ensures that the Earth will remain full of life rather than turn barren and into a lifeless ball of rock without Sun.
vital statistics
The Sun is 1 390 000 kilometres in diameter and about 109 times wider than Earth. It has 8 planets orbiting and it takes 25.4 Earth days to rotate on it's axis. The core has a temperature of 15 million degrees Celsius. The energy released in the core of the Sun takes one million years to pass through the radiative zone and convective zone and reach the surface. The mass of our Sun is 333 000 times Earth's mass. It's density is 1.41 times the density of water and it's gravity is 27.9 times the Earth's gravity. The Sun has a very large large and complex magnetic field. The magnetic field at one place on the Sun is about twice as strong as the field on the surface of the Earth's. This magnetic field is what keeps our solar system together.
structure
The Sun is thought to consist of the following layers:
- Core - where thermonuclear reactions occur and hydrogen fuse to form helium.
- Radiation Zone - where heat is carried from the core outwards by radiation.
- Convective Zone - where heat is transferred by convection of gases.
- Photosphere - the surface of the Sun.
- Chromosphere - a layer extending above the surface.
- Corona - diffuse, invisible under normal conditions and emits high-energy particles ('solar wind').
Energy
The Sun is power generated inside where the dense 'heart' is. As over 90% of the Sun is hydrogen (it being the simplest of element and building block for all other elements) it can produce 'mother chemical' elements. It also provides energy for life on Earth. The Sun does this by radiating energy, that has been generated, through a series of nuclear reactions. Nuclear reactions involve the centres of atoms splitting or joining together to form different elements. This process is called fusion. In both of these processes, mass is converted to energy.
While the Sun produces about 3.86 x 10^27 joules of energy each second, the quantity of energy that reaches the Earth is not more than 2% of what the Sun actually gives off.
While the Sun produces about 3.86 x 10^27 joules of energy each second, the quantity of energy that reaches the Earth is not more than 2% of what the Sun actually gives off.
Sunspots
Sunspots are dark spots that appear from time to time on the Sun's surface. They are usually only visible through a telescope and are about 4300K cooler than the surface of the Sun (6000K). As sunspots wax and wane, they can vary in number from as many as 200 to one. they also differ in size, with diameters from 2500km to 50000km. it is known that the bigger the sunspot, the longer they last.
A German pharmacist and amateur astronomer named Samuel Hemrich Schwabe (1789-1875), discovered the regularly occurring cycles of sunspots. He found what appeared to be a 'dark spot' on the surface of the sun while busy searching for an unknown planet passing in front of the Sun. He also noticed a regular variation while making observations every day possible from 1826 to 1843. It appeared to be a maximum of sunspot activity about every 11 years. This cycle of increasing and decreasing of sunspots was then confirmed by many other more experienced astronomers with observations ranging from 9.5 to 11 years between periods of maximum activity.
A H-R graph plotting the temperature and magnitude of the suns' sun spots is shown below.
A German pharmacist and amateur astronomer named Samuel Hemrich Schwabe (1789-1875), discovered the regularly occurring cycles of sunspots. He found what appeared to be a 'dark spot' on the surface of the sun while busy searching for an unknown planet passing in front of the Sun. He also noticed a regular variation while making observations every day possible from 1826 to 1843. It appeared to be a maximum of sunspot activity about every 11 years. This cycle of increasing and decreasing of sunspots was then confirmed by many other more experienced astronomers with observations ranging from 9.5 to 11 years between periods of maximum activity.
A H-R graph plotting the temperature and magnitude of the suns' sun spots is shown below.
Emissions
Solar wind
Solar wind is part of the Sun's corona which stretches outwards to the edge of
our milky-way galaxy. It is a stream of charged particles which spreads out from
from the Sun in all directions. For these particles to reach the Earth from the Sun,
it usually takes about one week. When the charged up particles in the solar wind
reach the Earth, most get trapped in the Earth's magnetic field. They sometimes
fall towards the ground near the North and South poles which then create curtains of
light in the sky, called 'auroras', or the northern and southern lights.
Flares
Flares are eruptions of gas and energy from parts
of the photosphere that have sunspots. There are more
solar flares when there are more sunspots.
coronal mass ejections
Coronal mass ejections are huge bubbles of gas entwined with
magnetic field lines. These bubbles of gas are ejected from the
Sun over the time period of a few hours. They may also reach up to
a hundred million kilograms in size. Once it is detached from the
Sun, it races away at speeds more than 7 million miles an hour.