Lecture Notes on the Sun's Structure and Composition

Flashcards covering the structure, composition, energy production, and observation of the Sun based on lecture notes.

What are the layers beneath the visible surface of the Sun?

The core, radiative zone, and convective zone.

What are the layers that make up the solar atmosphere?

The photosphere, the chromosphere, and the corona.

What are granules on the Sun?

Hot, bright features on the Sun's surface caused by upwelling convection currents.

What happens when solar wind particles reach the vicinity of Earth?

They produce auroras, which are strongest near Earth’s magnetic poles.

What two elements make up 98% of the Sun's mass?

Hydrogen and helium.

What are sunspots?

Dark regions on the Sun where the temperature is up to 2000 K cooler than the surrounding photosphere.

How can we calculate how fast the Sun turns on its axis?

By observing their motion across the Sun’s disk.

Does the Sun rotate at the same rate at its equator and poles? If not, where is it faster?

More rapidly at its equator than near the poles.

What is the source of the Sun's energy?

The fusion of hydrogen to form helium.

What is the series of reactions required to convert hydrogen to helium called?

The proton-proton chain.

What formula gives the amount of energy converted from lost mass during hydrogen fusion?

E = mc2

What do we know about the sun regarding its equilibrium and energy output?

That the Sun is in hydrostatic equilibrium (neither expanding nor contracting) and puts out energy at a constant rate.

How is the energy generated in the center of the Sun carried to the surface?

By radiation and then convection.

What observational data can provide information about the Sun’s interior?

Helioseismology and neutrinos.

What has helioseismology shown about the Sun's interior?

The composition of the interior is much like that of the surface (except in the core) and the convection zone extends about 30% of the way from the Sun’s surface to its center.

What happens to electron neutrinos during their journey from the Sun to Earth?

Two-thirds of them are converted into different types of neutrinos.