Observing our Sun

Observing our Sun By Damian and Jack 7K

A little about the Sun The Sun is a star at the centre of the Solar System and it is almost perfectly round and consists of very hot plasma with magnetic fields. The Sun has a diameter of 1,392,684km so roughly around 109 times as big than the Earth. Its mass is 1.989E30kg approximately 330,000 times the mass of Earth and Its mass accounts for about 99.86% of the total mass of the Solar System. Almost 3 quarters of the Sun’s mass is Hydrogen, and the rest is mostly Helium, the remainder 1.69% (which is 5,600 times the mass of Earth) has heavy elements including Oxygen, Carbon, Neon and Iron. The sun also looks like a giant fire ball.

Some more about the Sun The surface temperature is 5,778K (5505°C). The “K” stands for kelvin, which is a unit used for measuring thermodynamic temperatures for space. The distance from Earth to the sun is 149,600,000km, which is very, very, very far away, and the radius of the Sun is 695,800km

Some more about the Sun The Sun formed approximately 4.567 billion years ago (And is also to this day only half way through it’s life cycle and still has four billion years) and from the gravitational collapse of a region within a large molecule cloud. The central mass became very hot eventually initiating a thermonuclear fusion in its core. The sun is a G-type main sequence star, based on spectral class and its designated as a yellow dwarf, but it is actually the colour white but may seem yellow because of the atmospheric scattering of blue light. The sun generates its energy by nuclear fusion of hydrogen nuclei turning it into helium, in its core the sun fuses about 620 million, tonnes of hydrogen each second.

Layers The core is the inner most part of the sun, in here gravity has squeezed the sun so much that the hydrogen compresses together to form helium and release energy through nuclear fusion. The core is about 150 times denser than water, and the temperature of 15 million degrees Celsius (28 million degrees Fahrenheit) The radiative zone is the layer above the core; the density slowly decreases when it moves away from core. Light produced from a nuclear fusion in the core travels out of the out of the radiative zone. This layer is not as dense as the core, but it is still dense that light from the core bounces around, taking about 100,000 years to move through the radiative zone. The Convection zone is the above the radiative zone. When the density of the radiative zone becomes very low, that the energy from the core in the form of light, it is then converted into heat. The heat from the edge of the radiative zone until it cools enough that it sinks to the core again.

Sun will expand When all the hydrogen has been burned, the sun will burn all the helium for about 130 million years more. During that time it will expand and engulf Mercury, Venus and Earth, and as it grows much larger, will become a red giant.

How the sun affects the seasons Since the way the earth is tilted and the way it orbits around the sun, the way the sun reflects light onto the earth matters. For example. When the southern hemisphere has summer, the northern hemisphere has winter, correct. Well this is because when we have summer, our part of the earth is tilted more to the sun making the sun beams direct to us but for the northern hemisphere, they aren’t directly pointed to the sun so the sun rays are obstructed a bit making less rays hit directly onto the northern hemisphere and the same thing works when we have winter and they have summer.

Core of the sun The core of the sun has a density one hundred and fifty times the density of the water on earth. The core has a temperate of 15.7 million kelvin (k) (or about 15,700,000 degrees Celsius). The inner core of the sun is basically the engine of the star and fuels the star. In the core of a star the intense heat ruins the internal structure of an atom and orderly, all atoms are broken down into their constituent parts. An atom is constructed of protons, electrons and neutrons. Neutrons have no electric charge and therefore do not interact much with the surrounding medium. As a result neutrons leave the core pretty quickly. The protons, which have positive electric charge, and the electrons, which have negative electric charge, remain in the core and cause the reactions which fuel the Sun. The charge neutral material of protons and electrons that makes up the core is called plasma. The high temperature provides the protons and electrons with a large amount of thermal energy and as a result they move around quite quickly. This motion, combined with the high density of the plasma, causes the particles to continuously slam into one another creating nuclear reactions. It is the fusion, or slamming together, of particular combinations of particles that provides the energy source of the Sun. There is a theory with something about the core can help us learn more about the ice ages.

The Sun will explode The sun is expected to turn into a massive red giant in about 5 billion years. During this period of time, the inner layers of the sun will become much hotter and the outer layers will become much cooler than they are now. Sadly still no life will be able to go on the sun. Considering how big the sun is, it might stretch out into the orbits of earth and mars but that might not happen. The oceans will boil away and there would be no atmosphere. Luckily, we won’t be alive and will not need to worry about this event. This will leave many questions though like: what will happen to our planet that we live on now?

What would happen if the sun turned into a white star If that were to happen then that would affect Earth in many ways. The reason being is because if the Sun were to lose all of its heat and gases then that would mean that the Earth would be getting no warmth and heat and that means that it would be really cold and people could die of hypothermia also it would be really dark, without the light of the Sun it would be very hard to get around because it would pretty much be pitch dark and you wouldn’t be able to see properly also if that were to happen would also lose solar energy because all of the light would have disappeared. So if the Sun were to lose all of its heat and gases that would have a tremendous cause on the Earth. Also if the Sun where to become a white dwarf star then that would mean that the Earth would be doomed because the process of that would equal to the Sun becoming a red giant eating up mercury and the heat of the Sun will catch on to Earth and end up burning Earth because of its hot temperature.

Why is the sun so important to us The sun is very important in our lives because the sun supplies us with heat and light, it is the most basic renewable energy source. We use it for solar energy and it give us heat, because if we didn’t, there would be no life on earth. Also, since the sun is so big, it has a large gravitational pull and that’s what keeps our planets in orbit and in perfect distance. It also provides us with vitamin D and that is essential for the skin. It also makes plants and other living things to grow. The sun makes energy for everything so if the sun were to disappear, there would be no energy for any thing and we wouldn’t be able to do our favourite things like: Running, playing sports, Gaming and many more things. This would also lead to no vegetation on earth to eat.

What would life be like without the sun If we didn’t have the sun we wouldn’t be able to live happy lives as we do every day! We wouldn’t be able to live without it, if we didn’t have the sun, plants and vegetation wouldn’t be able to grow and neither would wildlife. It also produces a lot of gravity which keeps us in orbit, otherwise Earth would float further and further and we would end up going past Neptune.

Surface The surface of the sun is very hot and boils as pockets of hot gas come up and sink back down. this gives the surface a grainy look, which is called granulation. Big explosions called Solar Flares rip through the surface and giant fountain like explosions called prominences that shoot very hot gases. Dark spots called sunspots often appear, they are about 1,500°C cooler than the area around them.

Granulation Granulation is when the area around dark sunspot groups becomes grey. Granules on the sun are caused by convection currents (thermal columns) of plasma within the convective zone.

Solar Flares A solar flare is a sudden flash of brightness over the Sun's surface, which is a large energy release of up to 6 × 10²⁵ joules of energy.

Prominences A prominence is a large, bright, gaseous feature that extends out from the sun’s surface. Prominences are anchored to the sun’s surface in the photosphere and extends out into the sun’s corona.

Solar winds The sun produces a solar wind, which contains charged particles such as electrons and protons. They escaped the suns gravity because of their high kinetic energy. Planets with strong magnetic fields such as Earth manage to deflect most of these charged particles as they approach.

Eclipses An eclipse occurs when an astronomical objects (in this case, the moon and the sun) is caused when one object comes between the viewer and another object. There are two types of eclipses, a solar eclipse and a lunar eclipse. A solar eclipse occurs when the moons shadow crosses the earths face. A lunar eclipse is when the moon moves in the earth’s shadow. They are also a very fascinating thing to see.

Solar Eclipse As seen from the Earth, a solar eclipse happens when the Moon passes in front of the Sun. The type of solar eclipse event depends on the distance of the Moon from the Earth during the event. A total solar eclipse occurs when the Earth intersects the umbra portion of the Moon's shadow. When the umbra does not reach the surface of the Earth, the Sun is only partially occulted, resulting in an annular eclipse. Partial solar eclipses occur when the viewer is inside the penumbra.

Lunar Eclipse Lunar eclipses occur when the Moon passes through the Earth's shadow. This only happens when the Moon is on the far side of the Earth from the Sun and is also needs to be a full moon. A lunar eclipse can be observed from nearly an entire hemisphere. Because of this reason, it is more common to observe a lunar eclipse from a given location. A lunar eclipse lasts longer, taking several hours to complete. Totality itself usually averaging anywhere from about 30 minutes to over an hour.

Sunspots Sunspots are temporary phenomena on the photosphere of the sun and are visible dark spots. They are caused by intense magnetic activity, forming areas of reduced surface temperature. Even though they are at roughly 3,000-4,500K (2,700-4,200°C), the surrounding area is at about 5,780K (5,500°C) leaves them visible as dark spots. If a sunspot was to be isolated from the surrounding area, it would be much brighter than the moon.

Analysing the telescope photos By looking at the photos we can see that, the sun looks like a white plate and the sunspots look like little black dots. To us it looks like a plate with specks of dirt on it. Before we looked through the telescope, we thought it was going to be a bright orange/yellow

Gods The sun influenced many ancient civilisations to make gods about the sun ranging from many different years and times. There are many different sun gods but we will be talking about our favourite three today.

Ra Ra the god of the sun, as the ancient Egyptians called him. By the fifth dynasty, Ra became one of the most important gods in ancient Egyptian legend. Ra was believed to rule the sky, the earth and the underworld. The Egyptians believed that the sun was Ra’s eye. The ancient Egyptians believed that Ra was swallowed every night by the sky goddess Nut, and was reborn every morning. The ancient Egyptians also believed that he travelled through the underworld at night. In the underworld, Ra appeared as a man with the head of a ram. Ra is said to have golden flesh, silver bones and hair made out of lapis lazuli. During the fourth dynasty, the pharaoh's were known as the sons of Ra. As Ra started to become more popular, Egypt wasted all of their money on building temples and statues of Ra.

Tonatiuh In Aztec Mythology, Tonatiuh was recognised as the god of the sun. The Aztecs c0nsidered him as the 5th sun, and that he took over when the 4th sun died out. Aztec theiories led that each sun was a god with its own cosmic era, the Aztecs believed they were still in Tonatiuh's era. According to the Aztec creation myth, the god demanded human sacrifices as tribute and without it would not move through the sky. It is said that 20,000 people were killed each year as sacrifices to Tonatiuh and the other gods. Even though this number is thought to be inflated either by the Aztecs, who wanted to inspire fear in their enemies, or the Spaniards, who wanted to vilify the Aztecs. The Aztecs were fascinated by the sun and carefully observed it, and had a solar calendar similar to that of the maya. Many of today's remaining Aztec monuments have structures aligned with the sun.

Apollo The ancient Greeks and Romans worshipped Apollo, the god of the sun. Apollo was not originally the sun god, he was the god of truth and prophecy, plagues, healing, arts, archery, agriculture, music and poetry. He was also believed to be able to bring ill health and plague. Medicine and healing are associated with Apollo, whether through the god himself or mediated through his son.

SOHO SOHO (Solar and Heliospheric Observatory), is a project of the international collaboration from ESA and NASA. The aim is to study the sun from its deep core to the outer corona and the solar wind. SOHO was launched on December 2, 1995. The spacecraft was built in Europe by an industry team led by Matra Marconi Space (now EADS Astrium) under management by ESA. Large engineering teams and more than 200 co-investigators from many institutions, supported by the PI’s in the development of instruments used in the spacecraft and in preparation of their operations and data analysis. NASA SOHO is made up of two modules. The Service Module forms the lower part of the spacecraft and provides power, thermal control, and telecommunications for the whole spacecraft and support for the solar panels. The Payload Module sits above it and houses all the scientific instruments used for studying the sun.

Yohkoh Yohkoh (AKA Solar-A), was a solar observatory spacecraft of the institute of space and astronautically science in japan, in collaboration with space agencies in the United states and the UK. It was launched into earth’s orbit during August 30, 1991 by the M-3s-5 rocket from kagoshima space station. It took its first image on September 13, at 1991 9:53 PM The satellite was three-axis stabilized and in a near-circular orbit. It carried four instruments: a Soft X-ray Telescope, a Hard X-ray Telescope, a Bragg Crystal Spectrometer, and a Wide Band Spectrometer. About 50 Mega bites were generated each day and this was stored on board by a 10.5 Mega bites bubble recorder .

Yohkoh (continued) Because the SXT utilized a charged couple device (CCD) as its readout device, maybe being the first X-ray astronomical telescope to do so, its "data cube" of images was both extensive and convenient, and it revealed very interesting detail about the behaviour of the solar corona. Previous solar soft X-ray observations. Many interesting new discoveries were also made. The mission ended after more than ten years of successful observation when it went into its "safe hold" mode during an annular eclipse on December 14, 2001 8:58 PM and the spacecraft lost lock on the sun. Operational mistakes and other flaws combined in such a way that its solar panels could no longer charge the batteries, which drained irreversibly; several other solar eclipses had successfully been observed.

FUN FACTS The suns star type is a yellow dwarf One million earths could fit into the sun The sun will eventually consume the earth The sun is almost a perfect sphere The sun travels 220 kilometres per second The suns distance from the earth changes each year The sun has a very strong magnetic field The sun weighs: 1,989,100,000,000,000,000,000 billion kilograms

Thank you for watching I would like to thank you for taking you time to watch this slide show on Damain and Jack’s presentation. Thank you very much and we hope you enjoyed our powerpoint and feel free to give us any feed back you would like to give us. After all, there are many ways we can improve our presentation. Thanks. (Total Words: 3,005 Unless I counted wrong!)

Bibliography http://www.answerbag.com/q_view/2402500 http://en.wikipedia.org/wiki/Sun http://sohowww.nascom.nasa.gov/about/about.html http://www.nasa.gov/mission_pages/hinode/solar_020.html http://en.wikipedia.org/wiki/Sunspot http://www.thesuntoday.org/overview/layers-of-the-sun/ http://www.factmonster.com/dk/encyclopedia/sun.html http://en.wikipedia.org/wiki/Solar_prominence http://en.wikipedia.org/wiki/Solar_flare http://csep10.phys.utk.edu/astr162/lect/sun/granulation.html http://en.wikipedia.org/wiki/Granule_(solar_physics) http://en.wikipedia.org/wiki/Eclipse http://en.wikipedia.org/wiki/Yohkoh

Bibliography (continued) http://ancienthistory.about.com/cs/grecoromanmyth1/p/Apollo.html http://www.sciencekids.co.nz/sciencefacts/space/sun.html http://ancienthistory.about.com/cs/grecoromanmyth1/p/Apollo.html http://www.ancientegypt.co.uk/gods/explore/ra.html http://en.wikipedia.org/wiki/Tonatiuh http://curiosity.discovery.com/question/why-sun-is-important http://www.ask.com/question/why-is-the-sun-so-important http://solar.physics.montana.edu/ypop/Spotlight/SunInfo/Core.html

Observing our Sun