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142 Cards in this Set
- Front
- Back
wavelengths |
from shortest to longest: gamma, x-rays, UV, visible, infrared, radio |
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frequency (definition) |
number of crests passing observer per second |
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velocity (what is it) |
directional speed |
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what are gamma rays |
energetic radiation; positron collide with material electrons cause gamma ray radiation |
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infrared wavelengths |
cause heat |
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radio waves |
longest wavelength; only wave not absorbed by earth's atmosphere & thus causes no distortion |
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ultraviolet radiation |
UV absorbed into atmosphere; can damage skin & eyes |
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visible light |
what we see; red, orange, yellow, green, blue, violet |
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x-ray wavelengths |
high energy; used to see bones; is absorbed by atmosphere |
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highest radiation to lowest |
x-ray, UV, visible light |
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photon energy |
inversely proportional to wavelength; proportional to frequency; short wavelength, high frequency |
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atom |
smallest particle of chemical element w/ characteristics/properties of element; dense & massive nucleus w/ protons/neutrons surrounded by electron |
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electron |
negative charged subatomic particle |
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proton |
positively charged subatomic particle |
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neutron |
subatomic particle with no electric charge |
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hydrogen atom |
1 proton, 2 electrons |
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helium atom |
2 proton, 2 neutron, 1 electron |
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plasma |
ionized gas of free moving electrons and protons; the fourth state of matter; all stars and most of the universe is plasma |
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lightest elements & most abundant |
hydrogen & helium (but not on earth) |
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what elements originated in the big bang |
hydrogen & helium |
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what is synthesized in the stars |
elements heavier than helium |
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what are the most abundant elements in the sun |
hydrogen (92.1%) & helium (7.8%) |
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carbon |
synthesized in stars |
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iron |
synthesized in stars; most abundant element on earth |
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fraunhofer absorption lines |
in photosphere and abundance of elements in sun |
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doppler effect |
shift, radial velocity, solar oscillations |
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zeeman effect |
polarization direction, splitting, strength, photosphere, visible light |
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magnetogram |
magnetisim across visible light "forbidden lines" |
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hydrogen alpha line |
chromosphere across face of sun; filaments and prominences |
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solar oscillation (time) |
5 minutes |
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light or neutrinos from sun to earth (time) |
8.3 minutes |
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duration of solar flare (time) |
10 minutes |
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traverse convection zone (time) |
10 days
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rotation period of sun at equator (time) |
27 days |
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sunspot cycle, magnetic activity cycle (time) |
11 years |
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complete magnetic cycle (time) |
22 years |
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period with few sunspots (time) |
70 years |
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duration of an ice age (time) |
100,000 years |
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traverse radiation zone (time) |
170,000 years |
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age of sun and earth (time) |
4.6 billion years |
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sun becomes a giant star (time) |
7 billion years |
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time of big bang |
14 billion years |
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RHESSI |
magnetic reconnection and gamma ray lines; pair annihilation and neutron capture with solar flares |
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SOHO |
solar oscillations, magnetic loops at different temperatures, oxygen ions move faster than protons in coronol holes, fast wind from open magnetism, slow wind from closed magnetism |
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SPITZER |
space telescope, infrared space observatory, |
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HIPPARCOS |
satellite from europe, first experiment for accurate measurements of celestial objects in sky |
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TRACE |
thin coronal loops, and coronal heating from magnetic reconnection of coronal loops |
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Ulysses |
first over solar poles, fast wind from coronal holes at poles, magnetic waves found above poles |
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Yohkoh |
x-ray sun, cusps demonstrate magnetic reconnection triggers solar flares in corona, twisted sigmoids predict explosions on sun |
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KEPPLER |
sent to discover earth-like planets orbiting other stars |
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HUBBLE |
launched into orbit in 1990 and is still in operation |
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SOLAR-B (Hinode) |
varying magnetic fields, solar flares, and winds |
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STEREO |
coronal mass ejections in 3D or from two directions, warning of intense geomagnetic storms and disruption of power lines |
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adams |
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babcock |
(solar dynamo) extrapolated a conceptually simple model; theorized about magnetic fields and dynamos |
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bethe |
proton-proton chain |
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barnard |
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davis |
solar neutrinos; developed the first neutrino telescope; |
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doppler |
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einstein |
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eddington |
nuclear reactions make the sun shine; reasoned the hydrogen is transformed into helium inside stars, which results in mass difference released as energy to power the sun |
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forbush |
cosmic rays and solar cycles; showed that cosmic rays are deflected by the sun's magnetism that is carried into interplanetary space by the solar wind, therefore number of cosmic rays that reach the earth carried with the 11 year cycle of solar activity |
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gamow |
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hertzsprung |
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jansky |
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keeling |
carbon dioxide in earth's atmosphere; first to measure the large amount of carbon dioxide in atmosphere |
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leighton |
solar oscillations; first to discover by subtracting images of sun taken in the long wavelength side of a stationary, non-moving absorption line, from an image taken in the short wavelength side of the line |
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maunder |
minimum of sunspots |
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milankovitch |
ice ages and distrubution of sunlight; developed milankovitch cycle; 3 rhythmic fluctuations of wobble/tilt of earth's rotational axis, and shape of earth's orbit that set major ice ages by altering seasonal distrubution |
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mcdonald |
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michell |
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pauli |
neutrinos and radioactivity; speculated that a second electrically neutral particle was created at the same time as the electron |
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reber |
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reines |
neutrinos from terrestrial nuclear reactor; proved existence of neutrino |
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russell |
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rowland |
ozone depletion; showed that man-made chemicals are destroying the ozone layer |
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rutherford |
atomic nucleus; showed that radioactivity is produced by the disintegration of atoms; discovered they emit alpha particles, consists of helium nuecli; mass of atom concentrated in nucleus (positive) balanced by electrons (negative) |
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schwabe |
discovered the sunspot cycle of 11 years |
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shwarzschild |
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stromgren |
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van de hulst |
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weizsacker |
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zeeman |
direction and strength of magnetic field; noticed subtle division and polarization of atom's spectral lines |
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hydrogen burning |
thermonuclear fusion of hydrogen nuclei into helium nuclei; process by which sun generates energy |
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proton-proton chain |
the process when two protons combine |
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positrons |
positive electron, gets released during process of proton-proton chain, anti-matter version of electron |
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electron nuetrinos |
no charge, very little mass |
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pair annihilation |
mutual destruction of electron and positron; w/ formation of energetic gamma rays |
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mass loss/energy gained |
mass loss converts into energy in the sun |
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tunneling |
two protons move close enough together to overcome barrier of repulsion; tunnels through it to cause a fusion |
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energy transferred in sun |
from core-> radiative zone-> convective zone |
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radiative zone |
radiation moves in zig-zag pattern; shroud of charged particles repeatedly absorbing, re-radiating and deflecting to control flow; 170,000 years for radiation to work its way out of zone |
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radiation diluted |
radiation is diluted as it travels through the radiation zone |
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convective zone |
energy takes 10 days to go from bottom to top of convective zone; |
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convection |
heated materials travel through convective zone; hot material-> cools by radiating sunlight into space; sinks back down to reheat and rise again |
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granulation |
images of photosphere, reveals tops of gases rising out of sun by convection |
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white light of photosphere |
layer of sun we can see; where we get sunlight and heat |
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beta-decay radioactivity |
disintegration of radioactive nucleus; neutron-> proton eject electron, nuetrino carries charge out |
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neutrino charge |
no electrical charge |
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velocity and mass |
equal to speed of light; no mass |
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solar neutrino problem |
transformation of solar neutrino into an undetectable form on their way out of the sun |
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neutrino detectors |
massive and underground |
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neutrino types |
electron, muon, tau, neutrino mass |
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solar oscillations |
5 minutes, from photosphere, produced by waves in convective zone; velocity increases with temp; |
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what's used to see far side of sun |
sound waves |
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sunspots |
megnetic field, the biggest is the size of the earth, 11 year cycle, connected by coronal loops in active regions, 20 years for complete cycle |
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solar flares |
ejects protons and electrons into space; interferes w/ ground-based radio & sattelites; 8 mins from sun to earth; result from magnetic energy stored in low solar corona |
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hard x-ray |
detected during impulsive phase of solar flare; electrons-> high velocity-> move down to footprints of coronal loops |
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soft x-rays |
emitted during decay phase of solar flare when material from chromosphere rises up to fill coronal loops in a process called chromospheric evaporation |
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radio emission |
detected during impulsive and decay phases; electrons-> high velocity-> mve down coronal loops-> produce gyrosnychrotronemission |
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gamma-rays |
produced during impulsive phase when flare-associated protons and heavier ions are beamed down into denser atmosphere |
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coronal mass ejections |
CME's; huge bubble of gas threaded with magnetic field lines; bigger than sun, long duration, compress earth's magnetic sphere, produce intense geomagnetic storms, and bright auroras, |
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two varieties of geomagnetic storms |
1. intense, sporadic, caused when CME encounters magnetosphere, more frequent at maximum in sun's 11 year cycle, bright auroras 2. low-level recurrent; 27 day cycle repitition period; produced by co-rotating interacting regions in solar winds; faint auroras |
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solar wind |
dominates charged particles in heliosphere; predicted from observations of comet tails |
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uniform fast wind |
origin in coronal holes, and regions of open magnetism and close acceleration |
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gusty slow wind |
origin in coronal streamers; regions of closed magnetism and distant acceleration |
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acceleration of particles in polar coronal holes |
heavier particles (oxygen ions) move faster than lighter particles (protons) acceleration generated by magnetic waves |
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alfven waves |
magnetic field disturbed-> tension acts-> generates waves that can propagate upward and dissipate energy in corona. |
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coronal streamer |
loop-like coronal structure in low corona; straddles magnetic neutral line on solar photosphere |
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cosmic rays |
not from sun, originate from exploding stars; |
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magnetosphere |
region in earth's atmosphere that dominates motions of charged particles; |
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heliosphere |
solar wind influence is dominant here |
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ionosphere |
radio waves bounced made by solar x-rays |
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stratosphere |
ozone layer made by solar UV |
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troposphere |
weather |
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auroras |
seen in polar regions; curtain from ground; oval from space; caused by high-speed electrons that excite oxygen and nitrogen in atmosphere to make the flourescence |
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coronal loops (solar x-rays) |
intense x-rays; remain stable for days/weeks/months explode when loop is twisted into unstable configuration |
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coronal holes (solar x-rays) |
fast solar wind
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cusp (solar x-rays) |
magnetic reconnection; place where oppositely directed magnetic fields, threading the two legs of the arch, are stretched out and brought together
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sigmoid (solar x-rays) |
gives notice of a few days if CME is going to collide with earth
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major ice age |
distrubution of sunlight on earth; interglacial warm period; incident sunlight |
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little ice age |
solar activity; few sunspots |
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ozone layer |
made by solar UV; destroyed by CFC's; ch |
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coronograph |
block out direct light from star so that nearby objects, which are otherwise hidden by stars glare, can be resolved |
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magnetograph |
producing magnetograms; maps of the magnetic field strength or direction on a distant object such as the sun |
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spectrograph |
spreads light or other electromagnetic radiation into its component wavelengths |
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absorption line |
a dark line of decreased radiationintensity at a particular wavelength of the electromagnetic spectrum, producedwhen radiation from a distant source passes through a gas cloud closer to theobserver. An absorption line can be formed when a cool, tenuous gas, between ahot, radiating source and an observer absorbs electromagnetic radiation of thatwavelenth |
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radiation belts |
a ring shaped region around a planet in which electrically chargedparticles - electrons, protons, and other ions - are trapped, following spiraltrajectories around the direction of the magnetic field of the planet |
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van allen belts |
radiation belts surrounding the Earth, containing electrons or protonsthat are mainly from the solar wind. |
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Coronal hole |
an extended region in the solar corona where the density and temp arelower than other places in the corona, and the coronal emission lines and theextreme ultraviolet and soft X-ray coronal emission are abnormally faint orabsent. The weak, diverging and open magnetic field lines in coronal holesextend radially outward and do not immediately return back to the Sun. Thehigh-speed part of the solar wind streams out from coronal holes. Thelow-density of the gas makes these parts of the corona appear dark in extremeultraviolet and soft X-ray images of the Sun, as if there were a hole in thecorona. Coronal holes are nearly always present near the solar poles, and canalso occur at lower solar latitudes. |
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coronal loop |
a magnetic loop that passes through the corona and joins regions, calledfootpoints, of opposite magnetic polarity in the underlying photosphere.Coronal loops can have exceptionally strong magnetic fields, and they oftencontain the dense, million-degreee coronal gas that emits intense X-rayradiation |
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coronal streamer |
a magnetically confined,loop-like coronal structure in the low corona straddling a magnetic neutralline on the solar photosphere. These high-density, bright coronal structureshave ray-like stalks that extrend radially outward to large distrances in theouter corona. At peak of the 11 year solar activity cycle, coronal streamersare located mostly near the solar equator and are a source of slow speed solarwind |