UNIT 2

Which of these layers of the Sun is the coolest?

A sudden, violent disruption (usually found near a sunspot) that releases an enormous amount of energy in almost all wavelengths in a very short amount of time is called a solar

From Earth, we can observe individual sunspots moving across the face of the Sun as the Sun rotates. Because the Sun is large, the time it takes for them to move from the eastern edge of the Sun's disk over the western edge, from our viewpoint, is about

From the outside moving in towards the centre of the Sun, which sequence of layers is in the correct order for the structure of the Sun?

The Sun goes through a regular cycle of activity on its surface due to changes in its complex magnetic field. This cycle can be tracked by watching for changes in the number of sunspots that appear on its photosphere. The activity is at a maximum when the sunspot number is at its highest. On average, how long does the cycle last before it repeats itself?

Stellar spectra tell us that ________ is the second most abundant element in the Sun.

As a direct result of the nuclear reaction process in the central core of the Sun, the only EM radiation released into the outer portions of the core and the radiative layer immediately surrounding it is

The Sun's photosphere layer is composed of convecting bubbles of charged gas particles.

Because of the tremendous pressure/density present in the Sun's radiative zone, photons of light trying to leave the core of the Sun take about __________________________ to travel through the radiative zone to the next outer solar layer.

In the nuclear fusion process, two protons (from hydrogen atoms) can only fuse in a region where the minimum temperature is greater than about ___________________.

The final step in transporting energy to the surface of the Sun is via convection.

Helioseismology has allowed scientists to develop a fairly sophisticated model of the internal structure of the Sun. This was possible through the study of ________________________ which astronomers began in the 1960's.

The constantly changing markings on the surface of the Sun which are actually the tops of hot convective cells rising in the photosphere are known as...

What causes the cycle of solar activity?

The charged particles blasting out of the Sun's atmosphere and traveling in the solar wind travel at almost 300,000 km/s.

Sunspots contain 2 zones - a cooler central umbra and a warmer outer penumbra.

The strongest magnetic fields in the photosphere lie near

The Sun sheds about _____________________ tonnes of particles each second in a continuous flow out of its outer atmosphere (known as the "solar wind").

Which is the net result of the proton-proton chain?

While the photosphere produces chiefly visible light, most coronal energy is in the form of

Who was the first scientist (1887) to notice that the sun's regular activity/sunspot cycle goes through occasional slumps, where for a number of years, there are significantly lower numbers of sunspots than normal - even in years of supposed maximum activity?

Astronomers estimate that every second the sun produces an amount of energy equivalent to the explosion of about....

How often does the Sun's entire magnetic field flip in its orientation?

In the 1970s, astronomers discovered that many of the expected neutrinos supposedly emitted by the Sun were not being detected. A theory evolved that they were oscillating between three states as they travelled away from the Sun. What are the three states that a neutrino can take?

In order to produce the 4 x 1026 watts of energy that it radiates, the Sun, through nuclear fusion, must convert _______________________ tonnes of hydrogen into helium each second.