* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Stars - Independence High School
Outer space wikipedia , lookup
Extraterrestrial life wikipedia , lookup
International Ultraviolet Explorer wikipedia , lookup
Corona Australis wikipedia , lookup
Observational astronomy wikipedia , lookup
Advanced Composition Explorer wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
Cygnus (constellation) wikipedia , lookup
Dialogue Concerning the Two Chief World Systems wikipedia , lookup
Perseus (constellation) wikipedia , lookup
Dyson sphere wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Astronomical unit wikipedia , lookup
H II region wikipedia , lookup
Tropical year wikipedia , lookup
Extraterrestrial atmosphere wikipedia , lookup
Aquarius (constellation) wikipedia , lookup
Solar System wikipedia , lookup
Planetary habitability wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Corvus (constellation) wikipedia , lookup
Stellar evolution wikipedia , lookup
Star formation wikipedia , lookup
Stars Chapter 25 The Sun • The Sun’s mass controls the motions of the planets • Less dense than Earth • High pressure and temperature causes gases to be plasma • Fusion- Combining of nuclei to form a larger nucleus • Fission- Separation of large nucleus into smaller nuclei • The Sun uses fusion to combine Hydrogen into Helium Anatomy of the Sun 1. Core- The Sun's nuclear "furnace," where fusion reactions initially combine hydrogen atoms to produce helium, yielding energy in the process. Anatomy of the Sun 2. Radiative Zone. Energy moves through a surrounding envelope of gas toward the Sun's surface. Anatomy of the Sun 3. Convection Zone. Big "bubbles" of hot gas transport energy to the surface. Solar Zones • Radiative Zone- 61% of interior from core. Heat moves directly to the surface • Convective Zone- 14% as heat moves to surface and cools, matter becomes more dense and sinks to be reheated Anatomy of the Sun 4.PhotosphereThe Sun's visible surface. Because of its high temperature, it glows yellow. • Photospherelowest layer of the atmosphere • 400 Km thick • Visible surface • Chromospheresecond layer • 2500 KM thick • 30000° K • Normally not visible Anatomy of the Sun 7. Corona- The Sun's outer atmosphere, which is heated by the magnetic field to millions of degrees. • Corona- The outermost layer • Several million kilometers thick • 1 to 2 million degrees K • Low density Solar Wind • Charged particles escaping from the corona • Reaches Earth at 400 km/s • Particles collide with atmospheric gases to form auroras Solar Activity • Sunspots- Dark colored, cooler spots on the surface of the photosphere; caused by magnetic fields • Coronal Holes- Low density gas areas of the corona usually over sunspots; provide escape for solar wind Solar Activity • Solar Flares- Eruptions of particles and radiation from the surface of the Sun; can cause problems with Earth’s communication systems • Prominence- An arc of gas that is emitted from the chromosphere or condenses in the corona; 50000° K Solar Activity Impact • • • • Solar activity cycle lasts 22.4 years 11.2 to maximum sunspots 11.2 to minimum sunspots Low sunspot activity cause a cooling of the Earth’s climate (Maunder Minimum) Spectra • Visible light arranged by wavelength • Continuous- No breaks in the band • Absorption- Bands caused by chemicals in the atmosphere absorbing certain wavelengths • Emission- Bright lines from a gas at certain wavelengths Star Groups • Constellations- groups of stars; usually named animals, mythological characters, or everyday objects • Circumpolar- Orbit the poles and can be seen year round • Seasonal- Orbit equator and can only be seen during certain times of the year Star Groups • Clusters- Group of stars that are gravitationally bound; open or globular • Binaries- Two stars gravitationally bound together; appear as one to the human eye. One is brighter than the other Star Light, Star Bright • Apparent Magnitude- The brightness of a star to the naked eye, regardless of distance from Earth. • Absolute Magnitude- Brightness of stars measured at equal distances • Luminosity- Amount of energy per second put out by a star. Star Measurement • Light Year- The distance the light will travel in a year = 9.461 X 10¹² km • Parsec- 3.26 light years = 3.086 X 10¹³ km • Parallax- Apparent shift in position caused by the motion of the observer Star Classifications • O, B, A, F, G, K, M- Based on spectral lines and temperature • O has hottest temperature and fewest lines • M has coolest temperature and most lines • Each letter is divided into 9 numbered categories Star Structure • 73% Hydrogen • 25% Helium • 2% Other Life Cycle • Star Formation- Cloud of interstellar gas called a Nebula which forms a Protostar • Protostar becomes hot enough for fusion to begin and become a star Life Cycle • Red Giant- Hydrogen is used up and star expands and cools; gases start to escape • Core of red giant is hydrogen and convert to carbon • Star shrinks and becomes White Dwarf • White Dwarf does not require heat source to continue Life Cycle • Neutron Star- Large cores collapse in on themselves • Supernova- Center of neutron star auses massive explosion blowing off the outer layers • Black Hole- Massive core that collapse in and with a gravitational field that sucks everything in.