Lecture #10 Flashcards: Understanding Solar Activity and Nuclear Fusion

These flashcards cover key concepts related to solar activity, nuclear fusion, and their implications for understanding the sun and its effects on Earth.

What is nuclear fusion in the context of the sun?

Nuclear fusion in the sun is the process where hydrogen protons combine to form helium, releasing energy.

What are sunspots and why do they appear darker than the surrounding area?

Sunspots are cooler regions on the solar photosphere that appear dark because they are approximately 4,000 Kelvin, compared to the photosphere's 6,000 Kelvin.

What is a coronal mass ejection (CME)?

A CME is a large expulsion of plasma and magnetic field from the sun's corona, often associated with solar flares.

How does solar activity vary and what is the cycle associated with this?

Solar activity varies on an 11-year cycle, marked by the rise and fall of sunspots, solar flares, and coronal mass ejections.

What evidence supports the occurrence of fusion in the sun?

The detection of solar neutrinos, which are produced during the fusion process, provides conclusive evidence of fusion in the sun's core.

What is the relationship between temperature, density, and fusion in the sun's core?

High temperature and high density in the sun's core are necessary for fusion to occur, enabling particle collisions needed for the fusion process.

Why are the sun's magnetic fields important in understanding solar activities?

The sun's magnetic fields are essential for understanding solar activities such as sunspots, solar flares, and coronal mass ejections.

What are solar flares and what causes them?

Solar flares are bursts of energy caused by the breaking of magnetic field lines, releasing a significant amount of energy and charged particles.

What is the effect of solar activity on Earth?

Solar activity can lead to disruptions in electrical systems, satellites, and can create visually stunning phenomena like the aurora borealis.

Explain the concept of luminosity in relation to stars.

Luminosity is the total amount of energy emitted by a star per second, independent of its distance from an observer.

Define the inverse square law in astronomy.

The inverse square law states that the apparent brightness of a light source decreases with the square of the distance from the observer.

What is the significance of solar neutrinos in astronomy?

Solar neutrinos help confirm nuclear fusion processes in the sun's core and allow scientists to measure the rate of fusion occurring.

What is the Parker Solar Probe?

The Parker Solar Probe is a spacecraft launched to study the sun's corona by flying through the sun's outer atmosphere.

What are the primary components released during the fusion of hydrogen in the sun?

During hydrogen fusion, a helium nucleus, two gamma rays, two positrons, and two neutrinos are released.

Why is temperature a measure of kinetic energy in gases?

Temperature is a measure of the average kinetic energy of particles in a gas; higher temperatures mean greater molecular motion.