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Studying the Sun. An Introduction. Why Study the Sun?. The Climate Connection Space Weather The Sun as a Star The Sun as a Physical Laboratory. The Climate Connection. http://solarscience.msfc.nasa.gov/whysolar.shtml. Ultraviolet (UV) View of the Sun.
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Studying the Sun An Introduction
Why Study the Sun? • The Climate Connection • Space Weather • The Sun as a Star • The Sun as a Physical Laboratory
The Climate Connection http://solarscience.msfc.nasa.gov/whysolar.shtml
Ultraviolet (UV) View of the Sun • UV view of the sun, taken by the SOHO satellite. • UV light causes sunburns • This is a false colour image since humans cannot see UV with their eyes. NASA/SOHO
Hurricane Katrina 28 Aug 2005 The energy that drove Katrina ultimately came from the sun http://www.katrina.noaa.gov/images/katrina-08-28-2005.jpg
Solar Wind and Space Weather This is an example of weather on earth, but weather in space is very different. What is going on here? http://torontoist.com/attachments/toronto_kevinb/2006_11_23FogInToronto.jpg
The solar wind and space weather begins with the sun’s corona expanding out into space • Corona is the outer atmosphere • A special camera blocks the light from the disc of the sun http://sohowww.nascom.nasa.gov/gallery/bestofsoho.html
Solar Wind 20 May 2008 9:03 UT Speed: 377 km/s Density: 6.35 protons/cm3 SOHO satellite Try expressing the density in a sentence.
The solar wind blows the tails of comets away from the sun Comet Hale-Bopp Photo Credit: A. Dimai and D. Ghirardo, (Col Druscie Obs.), AAC
The solar wind is a danger to astronauts and satellites Canadian astronaut Hadfield attached to Canadarm Canadian RADARSAT-1 http://www.space.gc.ca/asc/app/gallery/results2.asp?session=&image_id=6 http://www.space.gc.ca/asc/app/gallery/gallery/hight/STS-100-115.JPG
The earth’s magnetic field without interference of Sun • Is there really a bar magnet in the earth? • Why is the magnet’s south end at the north pole? http://stargazers.gsfc.nasa.gov/resources/magnet_in_space.htm
Notice how the magnetic and geographic poles are different. What defines the geographic north pole?
Solar wind distorting the earth’s magnetic field Not to scale artist’s depiction. http://en.wikipedia.org/?title=Geomagnetic
Aurora Borealis seen from space Credit: NASA
Aurora Borealis seen from rural Eastern Ontario, 2004 Credit: Terence Dickinson, Editor SkyNews magazine
Aurora Borealis seen in rural Eastern Ontario, 2004 Credit: Terence Dickinson, Editor SkyNews magazine
Aurora Borealis seen from Wapusk National Park, Manitoba http://i-eclectica.org/category/imagery/
Perseus Cluster of Galaxies Our sun can help us understand the billions of stars in the billions of distant galaxies & those in our own galaxy, the Milky Way Canada-France-Hawaii Telescope / Coelum
Milky Way Galaxy • Our own galaxy has billions of stars, our sun being just one of them! • A photo from a location with low light pollution http://en.wikipedia.org/wiki/Image:Milky_Way_IR_Spitzer.jpg
Inside an Experimental Fusion Reactor(Joint European Torus reactor) …attempting to recreate the sun in a lab to find a new source of energy http://en.wikipedia.org/wiki/Image:JointEuropeanTorus_internal.jpg
This magnet has unchanging magnetic lines http://www.teachnet-lab.org/ps101/bglasgold/magnetism/magnetism2.jpg
The twisting of the sun’s magnetism Differential rotation: different speeds at different locations above and below equator twist the lines of magnetism
Sun vs Earth Magnetism Sun’s magnetism is complicated Earth’s is relatively simple http://www.windows.ucar.edu/tour/link=/sun/sun_magnetic_field.html
The Sun’s complicated magnetism • The sun’s magnetism, always changing, is more complicated than the Earth’s magnetism • the sun’s magnetism forms these prominences into loops
Flares are formed by magnetic lines Titanic solar flares dwarf the earth by comparison NASA/SOHO
Galileo 1564-1642 …was credited with discovering sunspots in 1612 using a telescope, but Chinese astronomers may have been the first using the naked-eye http://www.galileo-galilei.org/pictures-galileo-galilei.html
Sunspots NASA/SOHO satellite image of sun with many sunspots
Sunspot Close-up • Granules are hot blobs of gas up to 1000 km wide • Dark spot is a sunspot where magnetism squashes the blobs http://solarscience.msfc.nasa.gov/feature1.shtml
Sunspot Magnetic Field Polarity http://solarscience.msfc.nasa.gov/feature1.shtml
Can you see any patterns in the data? Sunspot Activity http://sidc.oma.be/sunspot-index-graphics/sidc_graphics.php
If the sun was as big as a basketball, earth would be only 2.2 mm in diameter
Pinhole camera geometry light ray
Pinhole camera optics Diameter of object Diameter of image Light rays