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58 Cards in this Set
- Front
- Back
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When a gas is completely IONIZED, it is only composed of what?
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Atomic nuclei and electrons.
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Name the three layers the Sun's atmosphere and when they are visible.
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Photosphere - Always
Chromosphere - Solar Eclipse Corona - Eclipse |
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What is a solar wind?
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Wind of charged particles that begins as a gas flowing outward from the Sun's corona.
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What are the Van Allen Belts?
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2 huge rings in E's Magnetic field.
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What is an Aurora?
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The result of the particles from the Sun colliding with gases in E's atmosphere.
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What are sunspots? In what way do they occur?
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Dark spots on the surface of the photosphere. In pairs with opposite magnetic polarities.
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How long is the solar activity cycle?
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22.4 years
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What are coronal holes?
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Areas of low density in the gas of the corona.
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What are solar flares?
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Violent eruptions of particles and radiation from the surface of the Sun.
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What is prominence? Where is it ejected from?
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An arc of gas that is ejected from the chromosphere.
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What is the name of the inner sunspot ring? The outer?
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Umbra, pernumbra
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The theory of special relativity (E=mc²) states that...
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Mass equals energy, & matter can be converted into energy.
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What is fusion?
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The combining of light-weight nuclei into heavier nuclei.
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What is fission?
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The splitting of heavy nuclei into smaller, lighter atomic nuclei.
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In the radiative zone... (80%)
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Energy is transferred from particle to particle by RADIATION.
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In the convective zone...
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Moving volumes of gas carry energy to the Sun's surface through convection.
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What is a spectrum? How is it arranged?
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A visible light arranged according to wavelengths.
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What are the 3 types of spectra?
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ACE - Absorption, Continuous, Emission
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The solar composition of most stars and the Sun is...
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73% Hydrogen, 25% Helium
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Constellations are, and contstellations resemble...
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Groups of stars that form a pattern in the sky - animal, myth character, everyday object
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What are the types of constellations that can always be seen and appear to move around the North pole of Earth?
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Circumpolar constellations.
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A cluster is... What are the two types?
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A group of stars that are gravitationally bound to one another. Open & globular.
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In a binary star... Both orbit...
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Only two stars are gravitationally bound to one another and both orbit a common center of mass.
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What happens in an eclipsing binary?
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Two starts alternately block eachother out and cause the total brightness to dip each time.
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A parsec is...
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The distance at which an object has a parallaz of 1 arcsecond.
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What is parallax? What is it caused by?
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The apparent positional shift of an object causaed by the motion of the observer.
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What is apparent magnitude?
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How bright a star appears to be.
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What is absolute magnitude?
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The brightness an object would have if it were placed at 10pc.
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What is luminosity?
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The energy output from the surface of a star per second.
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What are watts?
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The units of energy emitted per second.
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Spectral lines provide info on what?
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Composition and temperature.
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When spectral lines are blueshifted...
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They are shifted toward shorter wavelengths. (To observer)
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What spectral lines are redshifted...
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They are shifted toward longer wavelengths. (Away from observer)
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The Hertzsprung-Russel Diagram is...
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A graph that relates stellar characteristics.
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Tha main sequence is...
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The broad strip along the HR diagram. Includes about 90% of stars
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Red giants are...
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Larger, cool, luminous stars
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What one factor makes one stars spectrum appear different from the others?
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Temperature.
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The temperature of a star determines --> The rate of nuclear reactions which determines -->
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Energy output (luminosity)
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__ is the hottest spectral type, and __ is the coolest.
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O , M
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Spectral types are based on (2)...
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Spectral lines and stellar temperatures.
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What 2 factors of a star determine nearly all of its properties?
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Mass and composition.
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The balance between gravity squeezing inward and pressure from nuclear fusion and radiation pushing outward is...
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Hydostatic Equilibrium
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A nebula is...
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A cloud of interstellar gas and dust that collapses on itself.
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A disk-shaped cloud contracting at its center that forms a new star is...
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A protostar.
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How long does it take for the Sun to convert all Hydrogen to Helium?
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10 billion years.
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Where outer layers expand once again and are driven off entirely by pulsations there is...
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Planetary nebula.
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Why is a white dwarf stable?
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Because it is supported by the resistance of electrons being squeezed together.
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The collapsed, dense core of a star that forms quickly while its outer layers are falling inward that contains only neutrons is...
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A neutron star.
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A supernova is...
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A massive explosion in which the outer portion of a star is blown off.
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A nebula collapses as a result...
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Of its own gravity.
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A small extremely dense remnant of a star whose gravity is so immense that not even light can escape its gravity field is...
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A black hole.
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The suns main two elements ... (%)
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90% Hydrogen, 8% Helium
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The heat of the Sun's core will...
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Strip away electrons from the nucleus of an atom.
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In E=mc²....
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E= energy
M= mass C= constant |
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What do solar flares cause?
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Auroras.
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Who discovered sunspots from his telescope?
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Galileo.
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What did Tycho Brache measure?
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Position of the stars and planets.
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What did Johannes Kepler write?
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The laws of planetary motion.
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