Karteikarten
Astronomy Final
Karten in diesem Stapel (141)
- 1light-yearthe distance light travels in a vacuum in one year
- 2Parsecsa unit of distance, 3.26 light-years
- 3AUsastronomical unit; the semimajor axis of Earth’s orbit, the average distance between Earth and the Sun
- 4Parallaxthe apparent displacement of an object due to the motion of the observer
- 5Celestial Spherean imaginary sphere of very large radius centered on an observer; the apparent sphere of the sky
- 6Altitudethe angular distance from horizon to star
- 7Azimuththe perpendicular measurement from horizon to star
- 8Declinationlatitude measurer
- 9Right ascensionmeasures longitude, given in a time
- 10Winter solsticesun’s rays lowest below equator
- 11Summer solsticesun’s rays highest above equator
- 12WeatherSummer sunrise above celestial equator, so hot
Winter sunrise below celestial equator, so cold
It is the angle the earth is tilted that gives us seasons. - 13Phases of the Moon
- 14Eclipses• Eclipses happen when the earth, moon, and sun line up together exactly (the moon must be a full or new moon)
- The moon is tilted by 5°, so it’s very rare that the geometry lines up perfectly which is why we don’t have an eclipse every full or new moon
- Lines up about twice a year for lunar eclipse and twice a year for solar - 15Ptolemygeocentric view of solar system, explained retrograde motion
- 16Copernicusheliocentric model, circular orbits
- 17Brahedetailed notes about everything in the solar system which Kepler used, saw a supernova and showed that the heavens weren’t fixed (questioned the geocentric model of the universe)
- 18Galileonot the center of the universe- moons that orbit Jupiter, Venus has phases
- 19Keplerlaws about rotation: (1) elliptical orbits (2) equal areas covered close and far from sun (3) set relationship for how long something takes to get around and how big the radius is between planet and solar system T2=R3
- 20Newtongravity, laws of motion: law of inertia, force=ma, every force has an equal and opposite reactionary force
- 21Edwin Hubbleobserved Andromeda and realized that there were other galaxies; first to think about Big Bang; observed spectrometry of galaxies and saw that they were red-shifted- discovered that galaxies were moving away from us
- 22Einsteinspatial theory of relativity—a quantity m of mass can in principle be converted into an amount of energy E according to a now famous equation E=mc^2 (c=speed of light); thermonuclear fusion
- 23Geocentric model of the UniverseEarth at center
- 24Heliocentric model of the universesun at center of the universe
- 25Electromagnetic SpectrumLong to short wavelengths: Radio Microwave Infrared Visible Ultraviolet Gamma rays (Rarely Must I Venture Under Xenon’s Gate)
- 26Visible lightRed is longer wavelength; purple shorter (we can see 400 to 700 nm → 4x10^ -7 to 7x106 -7
- 27Opacity of Earth's atmosphereatmosphere absorbs infrared and ultraviolet wavelengths
- 28Electromagnetic wave of Light
- 29Wavelengththe distance between two different wave crests, measured in lambda
- 30Frequencythe number of crests or troughs of a wave that cross a given point per unit time; the higher the frequency, the shorter the wavelength
- 31speed of wavewavelength x frequency
- 32Black body radiation
- 33Black body radiationHotter objects are brighter and “bluer” than cooler objects
- 34Wien's lawA relationship between the temperature of a blackbody and the wavelength at which it emits the greatest intensity of radiation
Continuous spectra for different temperatures; at higher temperatures, there is more energy at all wavelengths and the peak of the spectrum shifts to smaller wavelengths - 35Bohr atom
- 36Absorption and emission of light by atoms—Kirchhoff’s laws
- 37Doppler Shift
- 38Refraction Telescopebends the light
- 39Refraction Telescope
- 40Reflection telescopethe redirection of light
- 41Reflection Telescope
- 42KeckGround-based telescope, Hawaii, giant optical telescope on a mountain made up of smaller hexagons
- 43SALTSouthern African Large Telescope, largest optical telescope in southern hemisphere
- 44LBTlarge binocular telescope, Arizona
- 45Areciboradio; Puerto Rico, largest radio telescope
- 46VLAradio; Very Large Array, New Mexico
- 47SpitzerOuter space telescope, CalTech
- 48Chandralayers; x-rays
- 49Solar System Formation
- 50Terrestrial Planetshigh-density worlds with solid surfaces, including Mercury, Venus, Earth, and Mars
- 51Jovian Planetslow-density planets composed primarily of hydrogen and helium, including Jupiter, Saturn, Uranus, and Neptune
- 52Definition of Planetmust orbit the sun DIRECTLY, has enough gravity that it formed in the shape of a sphere (cuts out things like asteroids), “cleared the neighborhood” rule: swept up all of the mass in its own orbit and secreted that mass onto itself
- 53Extrasolar Planeta planet orbiting a star other than our Sun
- 54Earth's AtmosphereTop to bottom: Ionosphere Mesosphere Stratosphere Troposphere (I Met Sarah Tuesday)
- 55Greenhouse EffectIncoming visible light from the Sun (short wavelength) is either reflected back to space by clouds of liquid droplets or solid particles or makes it to the ground to heat it up. Visible light passes through H20 and CO2 gases. Since the ground is much cooler than the hot Sun's surface, it reradiates the energy in the form of infrared light (long wavelength) instead of visible light. Greenhouse gases (like H20 and CO2) and clouds reflect some of the infrared light back to the ground trapping the heat close to the surface. Some infrared light does escape back to space-otherwise the surface would continually get hotter and hotter.
- 56Van Allen Radiation Beltwhere particles from the sun are stopped by the magnetic belt of the planet; Outer Belt- negative electrons; Inner belt- positive protons → when field enters atmosphere, it causes particles to glow which creates the Northern lights (or Aurora)
- 57Escape Velocitythe velocity it takes to exit from atmosphere; on Earth the escape velocity is approximately 11.2 km/sec
- 58Mariadark spots on the moon from volcanic processes
- 59Highlandswhitish spots on the moon
- 60Ejecta blanketlayer of dust that covers the surface of the Moon
- 61Scarpsurface feature of Mercury; cliff that is formed by extreme heating and cooling-cracks like an eggshell
- 62Mercury's AtmosphereNone, too hot, all the gases have left
*Note: Atmosphere or lack of depends on temperature and gravity - 63Venus• Venus is 850°F because it’s atmosphere is greater than that of Mercury, so it holds onto more of the heat. Atmosphere is 96% carbon dioxide whereas on Earth it’s only a few percent. The clouds are made of sulfuric acid.
• Gaseous because so hot, immense pressures so could never send something in and land it, the closest planet to the size of Earth - 64Mars's Atmosphere90% carbon dioxide
- 65Olympus MonsHuge ass volcano on Mars
- 66Marinerison Mars; similar to Grand Canyon except deeper and wider
- 67Dust DevilMini tornadoes on Mars that just move the fucking dust around like a dumb ass hoe
- 68Mars's Moonsmore like asteroids, look like big rocky potatoes
- 69Mars (why red)covered in rust from amounts of Iron and Oxygen
- 70Why do we explore planets?to look for signs of life or signs that a planet could sustain life; to gather information about our universe
- 71Jupiter• The movement of the bands is what causes so much turbulence and so many storms. The different colors of the bands mean one is going up and one is going down (conflicting temperatures)
• Has a magnetic field that is 14 times stronger than the Earth’s field, strongest magnetic field in the solar system other than the Sun
• Rings come from tiny rocks that get caught in gravity of planet and get broken up and turned into ring.
• Big red spot: a storm that has been going on for at least 300 years, twice the size of Earth - 72Galilean Moons4 closest moons to Jupiter first observed by Galileo; Innermost to outermost- Io Europa Ganymede Callisto (I Eat Good Cookies)
*Note: All have solid surfaces - 73Io• Io is the only other known object in the solar system that has ACTIVE volcanoes. On Io, the tidal forces tear up the moon. Can calculate the gravity by observing how high the spray of the volcano is.
- 74Europa• Europa has a lot of cracks caused by the tidal forces. It is entirely covered in frozen water ice. Has some liquid water underneath because of the tidal forces. This is one of the few places in our solar system that could support life.
- 75Ganymede• Ganymede and Callisto are a little bit bigger than Earth’s moon
• Ganymede is very similar to Earth’s moon, has Maria, and is largest moon in our solar system. - 76Callistoa little bit bigger than our moon; has water ice
- 77Saturn• Rings are made mostly of ice and rock. Moons that tried to form or were successful in forming but then the tidal forces broke them up.
• The rings are very thin and are located right at the equator
• The gaps between rings are where the bigger moons are that can resist the tidal forces.
• Saturn has 62 known moons- mostly small and rocky and icy
• Cassini launched in 1997 - 78Titanlargest moon of Saturn- first moon we found that has a really thick atmosphere- 90% Nitrogen, also has other gasses like Methane (a hydrocarbon which means that it’s a building block of carbon based life form as we know it)- very cold- around the poles of Titan there are what appears to be lakes which are not water lakes but probably methane or hydrocarbon lakes
- 79Uranus2-3% Methane, no Ammonia → makes the blue color
27 moons - 80Why isn't Pluto a planet?Hasn't cleared its neighborhood
- 81Asteroids versus Meteoroids• Asteroids and meteors are both rocks in space. Asteroids are bigger than 100 meters across. Meteors are smaller than 100 meters across. Most of the asteroids and meteors reside between Mars and Jupiter in the asteroid belt. They can also exist (and be stable gravitationally) at the LaGrange point (Trojans).
- 82Meteoroid, Meteor, MeteoriteMeteoroid: in space
Meteor: trail of light that we see in the sky
Meteorite: lands on planet's atmosphere - 83Meteor Showerwhen we pass through an area in our orbit where there’s debris from asteroids, comets, or meteoroids
- 84Oort cloudthought that most of the comets have come from this Oort cloud, on the outskirts of the solar system
- 85Kuiper beltinhabited by Pluto-like objects, small moon-sized ice and rock
- 86Parts of a comet• Nucleus: dry ice held together by water ice plus dust and organic compounds
• Blue tail: ion tail
• Tail pointed away from the sun because solar wind
• White Tail: dust tail; see reflected sunlight from the dust
• Hydrogen Envelope: starts to form when the sun starts to defrost ice - 87Luminositymeasures the intensity of light, proportional to R2T4
- 88Parts of the SunInner to Outer: Core, Radiation Zone, Convection Zone, Photosphere, Chromosphere, Corona (Corn Reproduction Company Produces Chewy Corn)
- 89Corefusion, hydrogen and helium, hydrogen turned into helium
- 90Convection Zonewhere heat rises and colder creates a circular motion
- 91Photosphereappearance of the sun, surface, once it reaches this really small layer the photons are released
- 92Chromospherehas absorption lines
- 93Coronaouter layer, really thin, heats up particles so that they become faster than the sun’s escape velocity and this creates solar wind (nobody knows why the corona is so hot)
- 94Sunspotsregions of intense magnetic fields, low temperature, in the photosphere, frequently found in groups but can be by themselves as well, umbra core and penumbra brighter outer core
- 95Sun Flaresejects clouds of electrons, ions, and atoms through the corona of the sun into space; increases when the sun is active
- 96Prominencesloops, go to corona
- 97Coronal Mass Ejectionspasses the corona into space, massive burst of solar wind and magnetic fields
- 98Solar Windan outward flow of particles (mostly electrons and protons) from the sun, the speed needed to reach escape velocity is what causes the wind
- 99Quiet Sunthe processes of the sun that put out 99.9% of the sun’s light/heat/energy, steady, doesn’t really change (fusion in the core, convective zone, released at the photosphere)—occurs when the magnetic fields are not tangled
- 100Active Sunrapid change, lots more flares and ejections, occurs when the magnetic fields are tangled
- 101Fusionpulling objects together and creating them into a larger object, happens when you take two nuclei and bring them together into a reaction to form a larger or heavier element (loss in mass which is released as energy which creates the light)
- 102Neutrino Problemonly found a third of the neutrinos they thought there would be, discovered there were three types of neutrinos
- 103Spectral ClassesOBAFGKM (Oh Boy A Fine Guy Kissed Me)
*Note: Our sun is a G2 star - 104Apparent and Absolute BrightnessApparent: how bright a star appears to us on Earth
Absolute: the apparent brightness that a star would have if it were at a distance of 10 parsecs
*Note: The lower a star is on the magnitude scale, the brighter it actually is if it seems bright from Earth - 105Temperaturehotter stuff on left side, cooler stuff on right side
- 106Distancecan find if you know how bright a star is
- 107HR diagram
- 108Trends of Main Sequence Starsmass gets smaller as spectral class gets cooler, luminosity decreases
- 109Main Sequence Stars
- 110Reflection nebulaeblue (same reason our sky is blue—methane)
- 111Planetary Nebulaforms at the end of a medium star’s life, releases outer layers of itself, forms a circular cloud around where the dead star will be
- 112Dark Nebulasometimes referred to as stellar nurseries
- 113How we find nebula if dust is blockingDust often blocks visible light, but not infrared light from these luminous stars (so we know they exist)
- 114Nebula 21 cm radiationmost reliable way to find star birth area, hydrogen spin (the proton and the electron want to be different because it takes lower energy, so the electron usually flips up and down)
- 115Death of sun-like star
- 116Novaa star that experiences a sudden outburst of radiant energy, temporarily increasing its luminosity roughly a thousandfold
- 117Type 2 Supernovadeath of all high mass stars
- 118Type 2 Supernovadeath of all high mass stars
- 119Type I Supernovawhen you have a low mass star with a binary star; the low mass star becomes a white dwarf and steals material from its binary star forming an accretion disk. If it gets too much mass then it explodes.
- 120Cepheid Variable Stara type of yellow, supergiant, pulsating star
- 121Neutron Stara very compact, dense star composed almost entirely of neutrons
- 122Pulsara pulsating radio source thought to be associated with a rapidly rotating neutron star
- 123Formation of Black Holes
- 124Schwarzschild Radiusthe radius from the center of the black hole at which point equals speed of light, once you’re in the Schwarzschild radius you’re stuck in the black hole no getting out, constantly changing as mass gets added into the black hole- gets bigger
- 125Event horizonthe outside circle of the black hole, nothing physically there, just a location
- 126Spiral galaxya flattened, rotating galaxy with pinwheel-like spiral arms winding outward from the galaxy’s nucleus
- 127Barred Spiral Galaxya spiral galaxy in which the spiral arms begin from the ends of a “bar” running through the nucleus rather than from the nucleus itself (what our galaxy is)
- 128Elliptical Galaxya galaxy with an elliptical shape and no conspicuous interstellar material, no longer making stars
- 129Irregular Galaxyan asymmetrical galaxy having neither spiral arms not an elliptical shape
- 130Milky WayOur galaxy, can see the spiral arms; the band of faint stars seen from Earth in the plane of our Galaxy’s disk
- 131Active Galaxya galaxy that is emitting exceptionally large amounts of energy; Seyfert galaxy, radio galaxy, or quasar
- 132Gravitational Lensing
- 133Dark matternonluminous matter that is the dominant form of matter in galaxies and throughout the universe; may account for the movement of the stars
Candidates: weakly interacting massive particles (wimps); faint, red, low mass stars; dim objects with small masses such as brown and white dwarf stars; black holes - 134Dark energya form of energy that appears to pervade the universe and causes the expansion of the universe to accelerate, but has no discernible gravitational effect
- 135Hubble Constanta constant proportion between how far away a galaxy is and how fast it’s traveling away
- 136Hubble's LawEquation: Ho=v/d, where v=speed away from us and d=distance
- 137Universe ExpansionEdwin Hubble—put light from galaxies into a spectrometer—discovered that almost every galaxy is red shifted—moving away from us
-The farther away it gets, the faster it’s moving away from us
-1st one to think about the big bang: the universe is expanding - 138Cosmic background radiationan isotropic radiation field with a blackbody temperature of about 2.725 K that permeates the entire universe
- 139Cosmic background radiationan isotropic radiation field with a blackbody temperature of about 2.725 K that permeates the entire universe
- 140Fate of the Universe
- 141Fate of the Universe (Open, Closed, Critical)Density greater than the critical density-closed universe;
Density equal to the critical density-critical universe;
Density less than the critical density-open universe
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- Karteikarten am Astronomy Final, erstellt von o.ensley am 13/12/2013.
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- o.ensley
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