THE SUN
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Contents
1. Know about SUN 2. SUN in the milky way 3. motion of solar system 4. sizes of stars 5. inside the sun
6. Heliosphere 7. Activities of sun 8. Missions to Sun
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Know about SUN 3 Our Sun is a normal main-sequence G2 star, one of more than 100 billion stars in our galaxy. Diameter : 1,390,000 km. (109 times that of Earth) Mass : 1.989 X 10^30 kg. (330,000 times the mass of Earth) Temp : 5800 k (surface) 15,600,000 K (core) Distance: 1.496 X 10^8 km(8 min 19 sec at light speed) The outer layers of the Sun exhibit differential rotation: at the equator the surface rotates once every 25.4 days; near the poles it's as much as 36 days. This odd behavior is due to the fact that the Sun is not a solid body like the Earth. Similar effects are seen in the gas planets. Chemically, about three quarters of the Sun's mass consists of H2, while the rest is mostly He. The remaining 1.69% (equal to 5,600 times the mass of Earth) consists of heavier elements, including O2, C, Ne and Fe, among others. The Sun is a perfectly normal example of a star, formed from the solar nebula 4.6 billion years ago. In about 6 billion years, the Sun’s core will run out of hydrogen. This may lead to the last counting days for solar system. THE AEROSPACE CLUB – NIT WARANGAL
Sun In the Milky way 4
The Sun is currently traveling through the Local Interstellar Cloud (near to the G-cloud) in the Local Bubble zone, within the inner rim of the Orion Arm of the Milky Way. Of the 50 nearest stellar systems within 17 light-years from Earth (the closest being a red dwarf named Proxima Centauri at approximately 4.2 light-years away), the Sun ranks fourth in mass. The Sun orbits the center of the Milky Way at a distance of approximately 24000–26000 light-years from the galactic center, completing one clockwise orbit, as viewed from the galactic north pole, in about 225–250 million years.
VORTEX MOTION OF SOLAR SYSTEM
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watch out https://www.youtube.com/watch?v=C4V-ooITrws
Size of Sun compared to other stars
6 See how small we are: https://www.youtube.com/watch?v=HEheh1BH34Q
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Inside the SUN 7
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HELIOSPHERE 8 The heliosphere is the outer atmosphere of the Sun and marks the edge of the Sun’s magnetic influence in space. The solar wind that streams out in all directions from the rotating Sun is a magnetic plasma, and it fills the vast space between the planets in our solar system. The magnetic plasma from the Sun doesn’t mix with the magnetic plasma between the stars in our galaxy, so the solar wind carves out a bubble-like atmosphere that shields our solar system from the majority of galactic cosmic rays.
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parts of heliosphere 9 Heliotail
As the heliosphere travels through the interstellar medium, it leaves a long heliotail in its wake wave, much like a boat travelling through the water. Bow Shock
Where the solar wind pushes against the competing force of the stellar wind, a bow (or shock) wave forms in front of the heliosphere. Termination Shock The point where the solar wind begins to interact with the local interstellar medium and slows down is called the termination shock. Heliopause It is thought that the heliopause is where the solar wind is not strong enough to push back against the stellar wind and is stopped by the interstellar medium. THE AEROSPACE CLUB – NIT WARANGAL
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Activities of Sun 11 Solar Wind The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons, and varies in temperature and speed over time. These particles can escape the Sun’s gravity because of their high kinetic energy. The solar wind creates the heliosphere, a vast bubble that surrounds the Solar System.
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CORONAL MASS EJECTION
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Coronal mass ejections (CMEs) are gigantic bubbles of electrified gas that billow away from the Sun. They can carry as much as 10 billion tons of solar material and trigger spectacular geomagnetic storms if they hit Earth's magnetosphere. CMEs, which usually travel at speeds between 500 and 1500 km/s, take 2 or 3 days to cross the 150 million km divide separating the Sun and Earth. To watch more http://www.thesuntoday.org/tag/coronal-massejection/
Solar cycle
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The Solar Cycle is the observed high and low sunspot activity that repeats about every 11 years. Sunspots are dark areas on the solar surface that contain strong magnetic fields that emerge through the solar surface and allow an area to cool slightly. This area appears as a dark spot in contrast with the very bright photosphere. Groups of sunspots, especially those with complex magnetic field configurations, are often the sites of solar flares. This makes the sunspot cycle a useful way to mark changes in the Sun’s activity.
On the surface 14 Surface Texture The photosphere is not smooth but rather looks as if it is composed of small grains or granules. These are the tops of convection cells that carry heat upward from deep within the Sun. Each granule in this image is about 1,000 km across.
Sunspots Scattered among the convection cells are large clusterings of strong magnetic fields that block the upward flow of energy to the surface. These areas of reduced temperature cause Sunspots, relatively cooler regions that appear darker because they are radiating less energy into space. THE AEROSPACE CLUB – NIT WARANGAL
Missions to Sun 15 Advanced Composition Explorer (ACE) Launch: 5 August 1997. Orbit: Near L1 Lagrange point. Solar and Heliospheric Observatory (SOHO) Launch: 2 December 1995. Orbit: L1 Lagrange point. Solar Dynamics Observatory (SDO) Launch: 2 November 2011. Orbit: Geosynchronous, 102 degrees W. Solar Terrestrial Relations Observatory (STEREO) Launch: 26 October 2006. Orbit: Sun-centric, approximately 1 AU. Aditya-1 Launch: Planned for 2015-2016. Aditya, will be launched by the Indian Space Agency (ISRO) to study the Sun's coronal mass ejections and magnetic field structures.
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Learn More
16 Coronal mass ejection video-
http://www.space.com/27266-1859-carrington-class-solar-stormpummeled-earth-s-magnetic-field-video.html To learn more about sun and solar system https://solarsystem.nasa.gov Life of sun http://www.universetoday.com/18847/life-of-the-sun/ visit http://www.planetary.org/ http://www.space.com/
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