The Sun Flashcards
>one of the 200 billion stars that make up the Milky Way Galaxy
>an “average star” compared to the other stars in the universe
Sun
Earth’s primary source of energy
Sun
The Sun’s Structure
- solar interior
- photosphere
- chromosphere
- corona
radiates most of the sunlight we see and therefore appears as the bright disk of the Sun
Photosphere
consists of a layer of incandescent gas less than 500 kilometers (300 miles) thick
Photosphere
grainy structure due to granules
Photosphere
this gas spreads laterally, cooling causes it to darken and sink back into the interior
Granule
each granule survives for only __ mins
10-20 mins
What gives the photosphere the appearance of boiling?
combined motion of old granules being replaced by new ones
up-and-down movement of gas
Convection
produces the grainy appearance of the photosphere
Convection
responsible for the transfer of energy in the uppermost part of the Sun’s interior
Convection
“color sphere”
Chromosphere
thin layer of hot, incandescent gases a few thousand kilometers thick
Chromosphere
observable for a few moments during a total solar eclipse (appears as a thin red rim around the Sun)
Chromosphere
contains numerous spicules
Chromosphere
flamelike structures that extend upward about 10,000 kilometers into the lower corona
Spicules
produced by the turbulent motion of the granules below
Spicules
the outermost portion of the solar atmosphere
Corona
visible only when the brilliant photosphere is blocked
Corona
normally extends a million kilometers or so from the Sun
Corona
streams of protons and electrons that boil from the corona
Solar Wind
travels outward through the solar system at high speeds (250–800 kilometers a second)
Solar Wind
interacts with the bodies of the solar system, altering its appearance
Solar Wind
Magnetic fields deflect..?
Solar Wind
upward from the photosphere..
although the coronal temperature exceeds that of the photosphere, it radiates much less energy overall because of..?
its very low density
the high temperature of the corona is probably caused by..?
sound waves generated by the convective motion of the photosphere
just as boiling water makes noise, energetic sound waves generated in the photosphere are believed to be
absorbed by the gases of the corona, thereby increasing its temperature
small, dark pores about 1,600 kilometers in diameter
Sunspots
appear dark only by contrast with the brilliant photosphere
Sunspots
Sunspots temperature
1,500 K less than that of the solar surface
over the course of 11 years, the yearly average number of sunspots slowly increases and then return to normal levels before rising again for the subsequent cycle
11-year sunspot cycle
huge cloudlike structures, made of chromospheric gases
Prominences
best observed when they are on the edge of the Sun
Prominences
2 Promiences
quiescent and eruptive prominences
appearance of a fine tapestry and seem to hang motionless for days at a time
Quiescent Prominences
material within them is continually falling like luminescent rain
Quiescent Prominences
rise almost explosively away from the Sun
Eruptive Prominences
reach velocities up to 1,000 kilometers (620 miles) per second and may leave the Sun entirely
Eruptive Prominences
brief outbursts that normally last an hour or so and appear as a sudden brightening of the region above a sunspot cluster
Solar Flares
during Solar Flares’ existence..
enormous quantities of energy are released across the entire electromagnetic spectrum, intensifying solar winds
following a strong solar flare, Earth’s upper atmosphere above the magnetic poles is set aglow for several nights
Auroras
Northern lights
aurora borealis
Souther lights
aurora australis
What is the source of sun’s energy?
Proton-proton chain reaction
Proton-proton chain reaction = ?
Nuclear Fusion
During nuclear fusion..
- hydrogen atoms fuse to produce helium
- mass of helium produced < mass of hydrogen that produced helium
- mass that is “lost” is converted into energy (light, heat and invisible forms of radiation)
Proton-proton Chain reaction = Nuclear Fusion
>four hydrogen atoms have a combined atomic mass of whereas the atomic mass of helium is 4.003, or 0.029 less than the combined mass of the hydrogen
>tiny missing mass is emitted as energy
>only a small percentage (0.7%) of the hydrogen in the proton– proton reaction is actually converted to energy
>the Sun is consuming an estimated 600 million tons of hydrogen each second, with about 4 million tons of it being converted to energy
>the by-product of hydrogen burning is helium, which forms the solar core
To initiate the proton–proton reaction, the Sun’s internal temperature must have reached several million degrees. What was the source of this heat?
COLLISION OF PARTICLES
When a gas is squeezed (compressed)
its temperature increases
Although all of the bodies in the solar system were heated in the same manner, the Sun was the only one, due to its ____ , that became hot enough to trigger the proton–proton reaction.
mass
