250 likes | 369 Views
The Sun. Photo from http://sohowww.nascom.nasa.gov/bestofsoho/bestofsoho.html. The Sun. Is a star Made of gases Is our primary source of energy. 70% hydrogen and 28% helium. Light (radiation). Image at http://science.nasa.gov/headlines/y2007/images/chromosphere/LimbFlareJan12_strip2.jpg.
E N D
The Sun Photo from http://sohowww.nascom.nasa.gov/bestofsoho/bestofsoho.html
The Sun • Is a star • Made of gases • Is our primary source of energy 70% hydrogen and 28% helium Light (radiation) Image at http://science.nasa.gov/headlines/y2007/images/chromosphere/LimbFlareJan12_strip2.jpg
How Big is the Sun? About 110 times wider than Earth Or 1.3 million times bigger than Earth Photo from http://sohowww.nascom.nasa.gov/bestofsoho/bestofsoho.html
How does our Sun compare to other Stars? Our Sun is a dwarf—medium mass • Active stars range in size from supergiants to dwarfs • Stars range from very bright (supergiants) to very dim (dwarfs) • Stars range from very hot blue on the outside (O class) to cool red on the outside (M class) Our Sun is a medium-bright dwarf Our Sun is in-between--yellow
Rotation At the equator, the Sun rotates once every 25.4 days Near its poles, the Sun rotates once every 36 days Known as “differential rotation”
Energy from the Sun • Nuclear chain reaction (hydrogen forming helium) • Releases radiation (gamma rays) • The gamma ray loses energy as it bounces around inside the Sun • It is finally released at the photosphere, primarily as visible light Image at http://solarscience.msfc.nasa.gov/interior.shtml
Inside the Sun • Core • Radiative Zone • Convection zone Image at http://solarscience.msfc.nasa.gov/interior.shtml
The Sun’s Atmosphere • Photosphere • Chromosphere • Corona Photosphere image: http://science.msfc.nasa.gov/ssl/pad/solar/surface.htm Chromosphere image: http://science.msfc.nasa.gov/ssl/pad/solar/chromos.htm Corona image: http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=191
The Photosphere • Photosphere: The ‘Surface’ of the Sun, and the layer from which light is given off • Sunspots: areas of the sun that look dark due to being cooler
Chromosphere & Corona • Chromosphere: middle layer of the Sun’s atmosphere • Corona: Largest layer of the Sun’s atmosphere
Solar Wind • Blows charged particles and magnetic fields away from the Sun • Charged particles captured by Earth’s magnetic field • Create Auroras or Northern and Southern Lights Image at http://solarscience.msfc.nasa.gov/the_key.shtml
Coronal Mass Ejection CMEs: large amount of electrically-charged gas are ejected suddenly from the Sun’s corona CMEs can damage satellites and interfere with radio and power distribution equipment
Prominences and Flares • Prominences- huge arching columns of gas • Flares: when gases near a sunspot brighten shooting outward
Radiation • Our Sun (and all active stars) emits radiation • Radio, infrared, visible, ultraviolet, x-ray and even some gamma rays • Most of the sunlight is yellow-green visible light or close to it The Sun at X-ray wavelengths Image and info at http://imagine.gsfc.nasa.gov/docs/teachers/gammaraybursts/imagine/page18.html and http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/sun.html .
Sun as a Source of Energy • Light from the Sun is absorbed by the Earth, unevenly to: • drive wind bands – which drive surface currents • drive deep ocean currents • drive water cycle • drive weather Credit: NASA GSFC Water and Energy Cycle http://www.nasa.gov/centers/jpl/news/grace-20061212.html NASA image at http://visibleearth.nasa.gov/view_rec.php?id=107
Our Sun is a Regular/ Small Star Image at http://www.gsfc.nasa.gov/topstory/20011210insidesun.html
Stars begin as a cloud of gas and dust called nebula Image at http://hubblesite.org/newscenter/archive/releases/2007/04/image/a/results/50/
Main Sequence Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star Image at http://hubblesite.org/newscenter/archive/releases/1997/26/image/a/
After billions of years a Main sequence star will turn into a Red Giant
By 5 billion years… White Dwarf:This happens when all that is left is the hot dense core Image at http://hubblesite.org/newscenter/archive/releases/nebula/planetary/1998/39/results/50/
Supergiant's and Supernovas Supergiant's: Extremely large (and unstable red giants Supernovas: The explosion that occurs when the supergiant’s core collapses Image at http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2000/28/image/a/format/web_print/results/50/
Black Hole • If the remaining dense core from a supernova collapses to a point • The gravity from this point is so strong that nothing can escape from it not even light. • If you were to shine a light into a black hole the light would simply disappear