Chapter 9 Quiz Flashcards
How massive is the sun compared to everything else in our solar system?
About 100 times bigger than the earth. Contains 99% of our solar system mass
In a giant ball of gas like the sun, whats the difference between the atmosphere and the interior?
everything below the photosphere is considered to be the interior since we cant really see through this layer of gas
What are the 3 layers of the atmosphere, how thick are they, where are they located (order)?
Photosphere(inner)- 400 km thick, the visible layer
chromosphere (middle)- 2000 km thick, what we see during a total solar eclipse, visible as a pinkish strip around the edges of the dark moon
Corona (outer)- extends out to millions of km from top of the chromosphere, the top layer (halo), very rarified gas, in transition zone, temp rises from 10,000 to 2 million degrees
What is the limb darkening? what causes it?
The photosphere appears darkest toward the edge, or limb, of the solar disk so we see different depths. the lower temps are toward the outer edges so we see a darker color when looking directly at the edges as opposed to looking at the center
Whats special about the photosphere?
you cannot see through it to the center of the sun because the gas is opaque. It contains granules
What are granules?
on the photosphere are dark, blotchy spots that form, disappear and reform. caused by convection currents of plasma within the suns convection zone
whats special about the chromosphere?
it is only visible during a total solar eclipse. it has spicules that flare up into the corona
what are spicules? where are they located?
jets of gas that surge up into the corona. located in the chromosphere
whats special about the corona?
it contains many ionized (very hot) elements even though it is farther from the hot core, it has low density, it is the source of solar wind (when gas escapes the sun and it projected out into space)
what do we mean by “the active sun”? How is it different from “regular” sun phenomena?
the active sun has granules, super granules, spicules, and solar wind?
What is a sun spot? how long does it last? how long is its cycle?
a sun spot is a darker, cooler spot. they last 1-4 days. they have an 11 year cycle. they reveal the solar cycle and suns rotation
Does the Sun rotate? What kind of rotation? How do we know that? How long does it take?
Yes, differential rotation. sunspot activity reveals that like the giant planets, different latitudes of the sun rotate at different rates. Fast on the equator (25 days)
Whats the basic underlying cause of sun spots (and other active sun phenomena)?
magnetic fields
What are plages?
hotter glowing compressed gas
What are filaments?
gas lofted from photosphere
What are prominences?
arches of hot gas, filaments sides
What are coronal hot spots?
located over sunspots, they act as conducts for gasses to flow from the sun
What are coronal holes?
areas where the Sun’s corona is darker, and colder, and has lower-density plasma than average because there is lower energy and gas levels.
What are solar flares?
high energy eruptions typically occur when sunspots collide, these release large quantities of high energy particles
What are coronal mass ejections?
spherical volume of high energy gas ejected
Whats SOHO?
Solar and Heliospheric Observatory- the satellite that took pictures of the sun
What do we know about the Sun’s shining/burning process?
Sun shines because core temperature is hot enough to fuse hydrogen into helium called thermonuclear fusion
What did Einstein say about Energy and Matter? What does that have to do with the Sun?
E= mc^2 – a small amount of matter can convert into a great amount of energy and this is how the sun heats and shines
How do you get nuclear fusion? What causes it in the Sun?
Hydrogen is squished and fuses into helium at temperatures above 10x10^6 K and the sun’s core is 15.5x10^6 K therefore allowing fusion to occur. The reaction causes gamma rays. Some of the mass of the hydrogen atoms is converted into energy in the form of light.
What’s Hydrostatic Equilibrium?
The balance of the inward gravitational force and the outward force of fusion within a star. This balance of forces is what keeps a main sequence star stable.
Where in the Sun does Fusion occur? How does the heat/photons get out? How long does that take?
Fusion occurs in the suns core; it takes 170,000 years
How large are the various parts of the interior – Core, Radiative, and Convective zones? What happens in each?
Core- thermonuclear reactions .25 solar radius
Radiative zone- energy from the core radiates .7 solar radius
Convection zone- energy is transported from radiative zone to outer layers through convection (rising and falling because of heat in a cycle)
