astronomy chap.8: the sun
equation for nuclear fusion on sun
4 ^1 H-> ^4 He + energy
what is the approximate average temp of the suns surface?
5800 K
hottest part of the sun is?
corona
the outermost part of the suns atmosphere
corona
the images produced by ____ reveal streamers in the corona that follow magnetic lines of force in the suns magnetic field.
coronagraphs
Violent bursts of ionized gas ejected from magnetic fields that flow outward in the solar wind
coronal mass ejection
atomic nuclei must overcome the ____ by colliding violently?
coulomb barrier
the babcock model of the solar magnetic cycle explains the sunspot cycle as primarily a consequence of the sun's?
differential rotation
when mapping the interior of the sun, astronomers must measure ____ as the photoshpere moves up and down.
doppler shifts
the ____ occurs when some of the energy in the convective motion of gas is converted into magnetic field energy.
dynamo effect
almost of the light we receive from the sun escapes from underneath its photosphere.(t/f)
false
helioseismology maps of rotation in the suns interior show that its internal gases rotate with equal periods.(t/f)
false
nuclear fusion in the sun is tremendously powerful.(t/f)
false
nuclear fusion within the sun proceeds step by step in a series of reactions called neutron-neutron chain.(t/f)
false
spicules can trigger communications blackouts and auroras on earth.(t/f)
false
sunspots numbers follow a seven year cycle.(t/f)
false
the layer above the chromosphere is the photosphere.(t/f)
false
the visible surface of the sun is composed of solid matter.(t/f)
false
when the sun generates its own energy, it uses weak forces to bind together atomic nuclei.(t/f)
false
stars, like the sun, generate their energy by the way of nuclear ____.
fusion
what is released from a proton-proton chain and is immediately absorbed by the surrounding gas, thereby heating it?
gamma rays
dark regions that give the suns photosphere a mottles appearance?
granules
what methodology do astronomers use to map the inside of the sun?
helioseismology
the most abundant gas making up the suns composition is ____.
hydrogen
two most abundant elements within the sun?
hydrogen and helium
the number of ____ visible on the sun varied in a cycle with a period of 11 years.
sunspots
what did galileo see on the surface of the moon?
sunspots
how many nuclear reactions occur in a proton-proton chain?
three
Flame-like structures that extend upward into the lower corona
spicules
which natural force binds atomic nuclei?
strong force
cool, relatively dark spots on suns photosphere appearing in group
sunspots
what is the average distance between the earth and the sun?
1 au
the chromosphere is roughly ____ times fainter than the photosphere.
1000
the corona can reach temperatures of to... ?
2,000,000 K
considering the complete magnetic cycle of a sunspot activity on the sun, how many years is the cycle?
22 years
the ____ of the solar disk is dimmer than the center, which is caused by the absorption of light in the photosphere.
Limb
why does the temperature of the corona rise with latitude ?
atoms are more ionized at higher latitudes
the ____ predicts that pairs of sunspots should occur where magnetic fields burst through the suns surface.
babcock model
what causes granulation of the photosphere?
convection
the solar wind extends to the _____, making an outer boundary of the solar system.
interstellar medium
granulation is evidence that energy in the photosphere..?
is flowing upward
what occurs on the surface of the sun during a solar cycle minimum?
little to no sunspot activity
historical records show that there were very few sunspots from about 1645-1715, a phenomenon known as the_____.
maunder minimum
subatomic particles released from the proton-proton chain of nuclear fusion
neutrinos
during nuclear fusion, four hydrogen nuclei fuse into how a many helium?
one
the _____ is a thin layer of gas from which earth receives most of the suns light.
photosphere
the layer in the sun from which visible photons most easily escape
photosphere
what is the correct order of suns atmospheric layers, from inner to outer?
photosphere, chromosphere, and corona
during the first proton-proton chain reaction, the weak force causes one of the protons to transform into a neutron and emit?
positron and neutrino
Arches of magnetic field visible in the chromosphere and corona
prominences
when two arches in a magnetic field encounter each other,___ can cause powerful eruptions called__?
reconnection events; flares
the pink color of the chromosphere is produced by what three colors of emission lines?
red, blue and violet
the magnetic polarities of sunspots _____ at the end of the 11 year cycle.
reverse
a breeze of low density ionized gas streaming away from the sun
solar wind
gas flows away from the sun in the ____, which can be considered an extension of the corona.
solar wind
why was the davis experiment only able to detect one-third of the neutrinos originally predicted?
the neutrinos spread into three different flavors evenly while traveling to earth
granulation is caused by convection currents just below the photosphere.(t/f)
true
sunspots are parts of active solar regions dominated by magnetic fields that encompass all layers of the suns atmosphere.(t/f)
true
sunspots tend to occur in groups, or pairs, with the magnetic field around the pair resembling that around a bar magnet.(t/f)
true
the corona is so dim that it is not visible in the earths daytime sky.(t/f)
true
the sun is a ball of hot gas held together by its own gravity.(t/f)
true
the upper chromosphere is hot enough to emit x-rays.(t/f)
true
astronomers often record solar images in the _______ part of the electromagnetic spectrum because the gaseous layers high in the suns atmosphere are very hot and emit most of their light at short wave lengths.
ultra violet
dark center of a sunspot?
umbra
astronomers can measure the magnetic fields of sunspots using the _____, which splits spectral lines into multiple components.
zeeman effect