CH 16

The Sun's surface vibrates from internal pressure waves reflecting off of the photosphere and passing through the solar interior. Since these waves penetrate deep inside the Sun, an analysis of the vibrations these waves cause at the surface can reveal unique information about the solar interior. The science of studying the vibrations on the surface of the Sun is known as helioseismology. If you were a helioseismologist, which of the following observational methods could you use to obtain information about the solar interior?

-Doppler shifts in solar spectral lines -Determine wavelengths and frequencies of individual pressure waves

Which of the following must occur for a star's core to reach equilibrium after an initial change in fusion rate?

-If the fusion rate initially increases, then the core expands. -If the fusion rate initially decreases, then the core contracts

If the last peak in sunspot numbers occurred in 2013, then the next solar max is ________.

2024

The Sun has sufficient hydrogen to continue fusing into helium for how much longer?

5 billion years

In which of the following layer(s) of the Sun does nuclear fusion occur?

Core

Layers of sun: Density

Core Radiation zone convection zone photosphere chromosphere corona

Layers of the Sun

Corona Chromosphere photosphere convection zone radiation zone core

Layers of the sun: Temperature

Highest->Lowest Core radiation zone convection zone photosphere

Layers of the sun: Pressure

Highest->lowest core radiation zone convection zone photosphere

The helium produced from the fusion of hydrogen has less mass than the hydrogen that goes into its formation. What happens to the missing matter?

It is converted into energy.

The density of the Sun is most similar to that of a) a comet. b) Jupiter. c) the Earth. d) interstellar gas. e) an asteroid.

Jupiter

The Sun spins on its axis roughly once each

Month

Which of the following layers of the Sun can be seen with some type of telescope? Consider all forms of light, but do not consider neutrinos or other particles.

Photosphere corona chromosphere w UV and x-ray telescopes

Solar Maximum Vs Solar Minimum

Solar Maximum: -occurs about every 11 years -solar flares are most common -orbiting satellites are most at risk -auroras are most likely in Earth's skies -sunspots are most numerous on the Sun Solar Minimum: -occurs about 5 to 6 years after solar maximum

What would happen if the fusion rate in the core of the Sun were increased but the core could not expand?

The Sun's core would start to heat up, and the rate of fusion would increase even more.

The time between successive sunspot maxima is about

a decade

A neutrino can escape from the solar core within minutes; how long does it take a photon to escape? a) minutes b) hours c) months d) hundreds of years e) about a million years

about a million years

Most of the Sun's ultraviolet light is emitted from the narrow layer called the ________ where temperature increases with altitude.

chromosphere

Energy moves through the Sun's ________ by means of the rising of hot gas and falling of cooler gas.

convection zone

Nuclear fusion of hydrogen into helium occurs in the ______.

core

We can see the Sun's _________ most easily during total solar eclipses.

corona

The standard solar model: two key parameters used are temperature and density. IF sun is in hydrostatic equilibrium, the model predicts that the sun's temperature should _______ and its density should _______ from its core to its surface

decrease, decrease

The "solar neutrino problem" refers to the fact that astronomers a) cannot explain how the Sun is stable. b) detect only one-third the number of neutrinos expected by theory. c) cannot detect neutrinos easily. d) are unable to explain how neutrinos oscillate between other types. e) cannot create controlled fusion reactions on Earth.

detect only one-third the number of neutrinos expected by theory.

The number of sunspots and solar activity in general peaks a) every 27 days, the apparent rotation period of the Sun's surface. b) once a year. c) every 51⁄2 years. d) every 11 years. e) approximately every 100 years.

every 11 years

According to the standard model of the Sun, as the distance from the center increases, the density decreases

faster than the temperature decreases.

As we move to greater and greater distances above the solar photosphere, the temperature in the Sun's atmosphere

first decreases and then increases

The primary source of the Sun's energy is

fusion of light nuclei to make heavier ones

Which of the following surface features provide evidence for solar convection?

granulation and supergranulation

The Sun is stable as a star because a) gravity balances forces from pressure. b) the rate of fusion equals the rate of fission. c) radiation and convection balance. d) mass is converted into energy. e) fusion doesn't depend on temperature.

gravity balances forces from pressure.

The proton-proton cycle involves what kind of fusion process? a) carbon (C) into oxygen (O) b) helium (He) into carbon (C) c) hydrogen (H) into helium (He) d) neon (Ne) into silicon (Si) e) oxygen (O) into iron (Fe)

hydrogen to helium

Which of the following changes would cause the fusion rate in the Sun's core to increase?

increase in core temperature decrease in core radius

Nearly all the visible light we see from the Sun is emitted from the __________. a) core b) corona c) photosphere d) chromosphere e) convection zone

photosphere

The observable ________ is a thin layer in which the solar material becomes suddenly much more opaque as we look deeper into the Sun.

photosphere

The ____________ is the layer of the Sun between its core and convection zone.

radiation zone

What is probably responsible for the increase in temperature of the corona far from the Sun's surface? a) a higher rate of fusion b) the Sun's magnetism c) higher radiation pressures d) absorption of X rays e) convection currents

the Sun's magnetism (the Sun's magnetic field acts like a pump to increase the speeds of particles in the upper corona.)