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72 Cards in this Set
- Front
- Back
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solar eclipse |
moon is directly between the earth and sun |
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umbra |
shadow behind earth |
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penumbra |
less complete shadow behind earth |
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complete lunar eclipse |
when moon is completely in earth's umbra |
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retrograde motion |
problem that plato and aristotle ran into/ they had theory that everything had circular orbit, but the problem was that it appeared everything went eastward at different speeds and sometimes moved west for a while (because believed in perfectly circular orbits |
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ptolemy's model |
solution to retrograde motion: epicycles (each planet has its own circle on the orbit (orbits on orbits) *in reality not a solution because not real. |
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heliocentric model |
developed by copernicus in 1473. earth revolves around the sun and rotates on its axis. no epicycles but still circular orbits |
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kepler's first law |
all planets move in elliptical orbits with the sun at the focus. |
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keeper's second law |
since elliptical orbits are uneven, line drawn from sun to planet sweeps out equal areas in equal time, no matter what speed its going at that point in the orbit |
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keeper's third law |
the square of the orbital period of a planet is proportional to the cube of its semi major axis |
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Newtons 3 laws of motion |
1: object at rest will remain so unless... 2: acceleration is produced when a force acts on a mass 3: for every action there is an equal and opposite reaction |
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light spectrum |
comes in a little bundle of energy photons H: gamma, X-rays, uv, visible (violet-> red), infrared (Heat), microwaves, cellular, fm, am: L |
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refracting telescope |
2 lenses that bend the light |
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reflecting |
1 lense, 1/2 mirrors, light rays bent by mirrors |
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emission lines |
rainbow lines on spectra come from excited gases (low density gas) |
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absorption lines |
when radiation passes through a cool gas, black lines on the spectrum where you can't see color cause there isn't enough light |
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Bohr model of the atom |
mass is primarily in the nucleus which has protons and neutrons with electrons in orbits
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isotope |
variation of an element. has more neutrons than protons |
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ion |
variation of an element that has lost or gained an electron. unbalanced and charged |
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coulomb force |
attraction between the nucleus and elections charges that holds the atom togehter |
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excited atom |
move an electron from a low energy to a high energy level through collision or absorbing a photon |
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photosphere |
visible surface of a star. comprised of hot ionized cases, freed electrons, ions all moving rapidly and colliding and radiating |
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blackbody radiation |
radiation emitted by a heated object (move bump faster--> more collisions) |
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Stefan- Boltzmann law |
relates temp of a blackbody to the amount of total radiated energy |
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granulation |
granules are dark edged areas of the sun that last for 10-20 min before fading and being replaced by new ones. emit blackbody. result from convection currents just below photosphere surface |
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convection |
what hot material rises, cools and sinks |
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supergranules |
regions over twice earth's diameter w/ 300 granules grouped together. result from slow currents last a day or two |
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sunspot |
11 year cycle, cool spots in the photosphere |
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active region |
chromosphere and corona above sunspots have powerful magnetic fields |
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dynamo effect |
ionized gas conducting, stirred by convection --> energy flows outward --> converted into the magnetic field |
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magnetic carpet |
looped magnetic fields extending through the photosphere. generated by turbulence below photosphere |
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maunder minimum |
1645-1715 there were very few sunspots and it coincided with a mini ice age on earth. solar activity on earth correlates to amount of solar energy earth recieves |
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doppler effect |
apparent change in wavelength of light due to motion at the source/observer you can tell by the color change redshift = receding blueshift= approaching |
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plasma |
ionized rotating gas --> currents --> strong magnetic field |
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nuclear fusion |
why the sun shines gravity pulls sun together --> high pressure/temp in core -->fusion of hydrogen, helium, energy released pushes back against gravity either combine or split. iron doesn't release energy either way |
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hydrostatic equilibrium |
balances of forces of gravity pulling in and extremely hot gas in interior pushing out |
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aurora |
trapped ionized particles in north and south poles where the magnetic field comes closest to earth (northern lights) |
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proton-proton chain |
series of reactions converting hydrogen to helium and energy |
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luminosity |
intrinsic brightness |
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flux |
apparent magnitude |
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absolute magnitude |
brightness if all stars were 10 parsecs away |
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spectral classification by temp |
OBA Fine Guy Kiss Me blue (40,000) --> red (3000) |
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binary stars |
balance each other out, are on opposite orbits that have a shared middle point of mass. like a teeter totter |
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interstellar medium |
dust and gas |
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protostar |
hot ball of relatively dense gas that radiates but doesn't fuse that can become a star. has the ability to contract because of gravity--> spin --> flattens to a disk -->heat increases --> hydrogen fusion begins --> main sequence star |
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leave the main sequence |
gravity compresses core more --> pressure/temp increase --> rate of reactions increase --> energy release increases --> outer layers expand and cool |
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CNO cycle |
hydrogen to helium is faster and more efficient than the proton-proton chain |
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how low mass stars die |
RED DWARFS don't die because they fuse too slowly and they are small enough that there is convection throughout |
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how medium mass stars die |
90% life on main sequence helium accumulates in core (hydrogen gone)--> can't resist gravity--> contract and temp increases --> hydrogen core fuses and outer layers expand --> radius increases dramatically --> surface temp decreases --> becomes red giant |
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how big mass stars die |
H depleted in core leaves MS burns through the He, Carbon, neon, oxygen, silicon cores and shells til it reaches iron collapses--> bounces back out off iron core type 2 supernova |
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type 2 supernova |
blows outer layers away --> huge energy release 10^44 j leaves behind shells of hot expanding ionized gas |
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type 1a supernova |
white dwarf accretes matter electron degeneracy pressure can't support it collapses and fuses at once blows up hugely visible from end of universe |
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nova |
binary system of white dwarf and red giant that builds up hotter and denser and blows up
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neutron stars |
huge. mass of collapsing star core is over 3 solar masses. but with tiny radius temp falls --> spins rapidly --> strong magnetic radiation can become a black hole |
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pular |
neutron star that you can see beams coming off of through change in emission lines |
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black holes |
if bigger than 25 solar masses/ nothing can stop gravitational collapse to 0 radius light can't even escape (its within the schwartzchild radius |
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escape velocity |
can only escape gravitational pull with correct launching force and distance from core |
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supermassive black hole |
mostly dormant, formed along with the galaxy |
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galaxy mergers |
results in rapid star formation (starburst)--> exhausts gas --> spiral galaxy |
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gravitational disruption between galaxies |
spherical cloud of stars w/o structure --> elliptical galaxy |
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elliptical galaxy |
core and halo structure. no young stars, dust or gas (would have gone supernova) old/red stars |
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active galaxy |
nucleus core is emitting a lot of energy in radio and X-ray waves have active black holes at center |
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quasar |
compact/ dense galaxies that are very distant and bright. newly formed, with a lot of star formation and active black hole at center mergers common early galaxies in universe now quieter |
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extra solar planet |
planet orbiting another star |
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wobble method of detecting extra solar planets |
the planet's orbit tugs the star back and forth can track movements of the planet based off the slight change in movement of the star based on its doppler shift away and closer |
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transent method of detecting extra solar planets |
measure time it takes the planet to pass between earth and the star (blocs the star's light) |
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hubble |
measured redshift and distance for a set of galaxies discovered we are not at the center of the universe and the universe is expanding and moving away from us |
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big bang nuclear synthesis |
3 min afterwards: cool enough to fuse neutron and protons into elements. 380,000 years later its cool enough that electrons can recombine with nuclei to make neutral atoms--> redshift |
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dark matter |
not luminous, unknown weakly interacting particle that constitutes 80% of all mass |
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gravitational lensing |
when light bends around galaxies and clusters due to the gravity of their mass. how we can see distant galaxies from earth |
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dark energy |
gravity slows the expansion rate of the universe resulting in: 1. expanding slower and slower forever 2. recollapsing into a big crunch type 1a supernova |
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lifetime of sun |
hydrogen and helium with race amounts of others. sphere of ionized gas (plasma) |
