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astronomy test 2
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52
Astronomy
Undergraduate 2
04/04/2011

Additional Astronomy Flashcards

 


 

Cards

Term
Prominences
Definition
eruptions on the solar surface in the chromosphere
Term
Photosphere
Definition
light on the sun originates here
Term
corona
Definition
outer atmosphere of the sun. made of hot low-density gas
Term
chromosphere
Definition
thin layer of bright gas. middle layer of sun's atmosphere
Term
granule
Definition
part of the photosphere; dark edged regions that last 10-20 minutes; pebble shaped
Term
convection
Definition
when hot fluid rises and cool fluid sinks
Term
solar wind
Definition
gas flows away from the sun in a breeze from the corona
Term
nuclear fission
Definition
generate energy by splitting nuclei of uranium
Term
nuclear fusion
Definition
generate energy by combining light nuclei into heavier nuclei
Term
sunspots
Definition
cool spots on the sun's surface caused by strong magnetic field
Term
zeeman effect
Definition
how astronomers study strength of magnetic field on the sun and provide evidence that sunspots have strong magnetic fields
Term
supergranules
Definition
regions of very slowly rising currents that last a day or two; two times Earth's diameter
Term
spicules
Definition
flamelike jets of gas extending up into the chromosphere; last 5-15 minutes
Term
solar flares
Definition
violent eruption on sun's surface in a loop shape (comes back to the sun)
Term
limb darkening
Definition
the decrease in brightness of the sun from its center to its limb
Term
limb
Definition
the edge of the apparent disk of the sun
Term
core
Definition
where most of the energy emitted by the sun is generated
Term
neutrinos
Definition
a neutral, massless particle that travels at the speed of light; created in the core of the sun
Term
solar cycle of sunspot maximum
Definition
11 years
Term
pattern of granulation
Definition
The granules are the tops of hot gas that have risen from the Sun's convective zone
Term
layers of sun
Definition
photosphere, chromosphere, corona
Term
top left. H-R diagram
Definition
hot, bright stars
Term
bottom left. H-R diagram
Definition
hot, dim stars
Term
top right. H-R diagram
Definition
cool, bright stars
Term
bottom right. H-R diagram
Definition
cool, dim stars
Term
main sequence
Definition
90% of all stars
Term
most common star
Definition
lower main sequence stars
Term
limit at lower end of the main sequence
Definition
there is a minimum temperature for hydrogen fusion
Term
hydrogen and helium
Definition
nuclear fuels that one solar mass star uses over the course of its entire evolution
Term
red giant
Definition
the sun departs from the main sequence and becomes:
Term
planetary nebula
Definition
the result of carbon detonation in a 1 solar mass star
Term
supernova
Definition
occurs when the core of a massive star collapses; elements heavier than iron are produced
Term
iron fusion
Definition
big stars can not get hot enough to generate energy this way
Term
terrestrial planets
Definition
few satellites, craters, small diameter, orbits inside asteroids, solid surface, and has high average density. Mercury, Venus, Earth/moon, Mars.
Term
condensation in solar nebula
Definition

atoms and molecules make droplets

earth= silicate grains Jupiter= icy grains Mercury= metallic grains

Term
young stars
Definition
have hot disks that surround them
Term
asteroid belt
Definition
between Mars and Jupiter
Term
solar nebula
Definition
created the present motions of the planets
Term
greenhouse effect
Definition
carbon dioxide traps infrared radiation
Term
dynamo effect
Definition
generates Earth's magnetic field in the molten metallic core
Term
lunar maria
Definition
lava plains of the lunar lowlands; younger than highlands
Term
breccias
Definition
evidence that the lunar surface was fragmented by meteorite impacts
Term
Caloris Basin
Definition
an impact basin filled with lava flows on Mercury
Term
lobate scarps
Definition
evidence that Mercury shrank slightly when it was young
Term
large-impact hypothesis
Definition
the Moon is poor in heavy elements like iron from the impact that occurred after Earth had differentiated heavy elements to its center
Term
Solar Nebular Theory
Definition
how planetary systems start: takes 100 million years, starts with a rotating cloud, all planets orbit sun in same direction, sun is rotating on axis in same direction, and most planets are spinning on their axis in same direction 
Term
Jovian planets
Definition
jupiter, saturn, uranus, neptune. large, low density, thick atmosphere, liquid matter, small solid pores, and have satellites/rings
Term
ceres
Definition
circular asteroids about the size of Mercury
Term
Kuiper belt
Definition
ice comets beyond Neptune
Term
aurora
Definition
glowing light display from the particles of solar wind smash on Earth at N and S hemispheres
Term
Maunder butterfly
Definition
sunspots disappear at the equator every 11 years
Term
4 H =
Definition

1 helium + energy.

burning hydrogen is how sun works

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