The Solar SurfaceThe Solar Surface

Luminosity Luminosity SunspotsSunspots Sunspot CycleSunspot Cycle Solar ProminencesSolar Prominences Differential RotationDifferential Rotation Solar WindSolar Wind AurorasAuroras

So How Much Energy Does the Sun So How Much Energy Does the Sun Release?Release?

Luminosity = the total power output of the Luminosity = the total power output of the SunSun 1 second of the Sun’s energy = 500,000 years 1 second of the Sun’s energy = 500,000 years

of energy for us!of energy for us! 3.8 x 103.8 x 1026 26 watts watts

380,000,000,000,000,000,000,000,000 watts!380,000,000,000,000,000,000,000,000 watts! That’s 380 septillion wattsThat’s 380 septillion watts

That’s 3,800,000,000,000,000,000,000,000 100 watt That’s 3,800,000,000,000,000,000,000,000 100 watt light bulbs!light bulbs!

3.8 sextillion light bulbs3.8 sextillion light bulbs $0.65/hr $0.65/hr

$4,111,599,999,920,000,000,000,000 hour$4,111,599,999,920,000,000,000,000 hour

$6,852,666,666,540,000,000,000.00 per minute$6,852,666,666,540,000,000,000.00 per minute

$114,211,111,109,000,000,000 per second$114,211,111,109,000,000,000 per second

• Magnetic field – flow of electromagnetic energy

• Sunspots = Darker and cooler areas on the Sun.

• Caused by a concentration of the Sun's magnetic field, which last from several hours to several months.

• Usually occur in pairs

Light and dark in this magnetic scan of the Sun indicate concentrated areas of intense magnetic fields.

Magnetism and Sunspots

Solar Solar ProminencesProminences They are eruptions caused by the flow of They are eruptions caused by the flow of

electromagnetic energy from sunspot to sunspot. electromagnetic energy from sunspot to sunspot. Cooler gases above the photosphere can often be seen Cooler gases above the photosphere can often be seen

flowing along magnetic field lines. flowing along magnetic field lines. A fairly common occurrenceA fairly common occurrence

Large Solar Large Solar Prominences Prominences

• This is the largest prominence observed.

• This huge prominence is 100,000 kilometers above the Sun.

28 Earths high

Solar Solar FlareFlare

An eruption of An eruption of energyenergy Does not Does not

“jump” from “jump” from sunspot to sunspot to sunspot like a sunspot like a prominenceprominence

Sunspot Cycle – Rising and falling levels in the number of observable sunspots. Solar maximum – numerous

observable sunspots Solar minimum – only a few

sunspots are visible Has a period of about 11 years

Sunspots migrate Mid-latitudes to equator Why?

What Causes the What Causes the Sunspot Cycle Sunspot Cycle and Migration?and Migration?

Not well understood!Not well understood! May be related to convection currentsMay be related to convection currents

As the convection cells rise and fall they may be As the convection cells rise and fall they may be dragging pockets electromagnetic energy up with dragging pockets electromagnetic energy up with them.them.

Differential RotationDifferential Rotation Period of 27 days at equator, 31 days at polesPeriod of 27 days at equator, 31 days at poles May stretch and distort magnetic fields May stretch and distort magnetic fields

The Solar WindThe Solar Wind A constant stream of particles that flow from the Sun’s

corona, with a temperature of about a million degrees and with a velocity of up to 450 kilometers per second.

The solar wind reaches out beyond Pluto's orbit (about 5900 million kilometers).

Auroras Auroras

They are also called Northern or Southern lights. These often brilliant and colorful phenomena, seen in the night sky usually closer to the poles.

They are caused by the impact of solar wind particles and magnetic forces on the Earth’s magnetosphere.

How is the Solar Interior Observed?

Prediction ModelsPrediction Models Computer Analysis and SimulationsComputer Analysis and Simulations

Sun QuakesSun Quakes Vibrations of the SunVibrations of the Sun

Releasing pressureReleasing pressure HelioseismologyHelioseismology

Doppler Radar Doppler Radar NeutrinosNeutrinos

Neutrinos – neutral particles released during Neutrinos – neutral particles released during fusionfusion

Rarely interact with anythingRarely interact with anything Neutrino Problem!Neutrino Problem!