Solar Flares, Prominences, the Solar Wind, and Coronal Mass Ejections

SOLAR FLARES
A solar flare is a magnetic storm on the Sun which appears to be a very bright spot and a gaseous surface eruption. Solar flares release huge amounts of high-energy particles and gases and are tremendously hot (from 3.6 million to 24 million °F). They are ejected thousands of miles from the surface of the Sun.

Solar flares were first observed by in 1859 by Lord Richard C. Carrington. He wrote that as he was watching the sun with a telescope, he saw "two patches of intensely bright and white light" near a huge group of sunspots. Just a few seconds later, the flare has disappeared.

It has been recently discovered that solar flares can cause sunquakes. Sunquakes are violent seismic events on the Sun. When a sunquake occurs, energy is released in seismic waves on the relatively fluid surface of the Sun. These waves radiate in concentric circles from the epicenter of the sunquake. These seismic waves seem to be compression waves (perhaps like "P" waves generated by earthquakes). Sunquakes would rate about 11.3 on the Richter scale. These huge quakes release about 40,000 times more energy than the 1906 San Francisco earthquake. Sunquakes were first observed by Alexander G. Kosovichev (Stanford University) and Valentina V. Zharkova (Glasgow Univ., UK).

SOLAR WIND
The solar wind is a continuous stream of ions (electrically charged particles) that are given off by magnetic anomalies on the Sun. The solar wind is emitted where the Sun's magnetic field loops out into space instead of looping back into the Sun. These magnetic anomalies in the Sun's corona are called coronal holes. In X-ray photographs of the Sun, coronal holes are black areas. Coronal holes can last for months or years.

It takes the solar wind about 4.5 days to reach Earth; it has a velocity of about 250 miles/sec (400 km/sec). Since the particles are emitted from the Sun as the Sun rotates, the solar wind blows in a pinwheel pattern through the solar system. The solar wind affects the entire Solar System, including buffeting comets' tails away from the Sun, causing auroras on Earth (and some other planets), the disruption of electronic communications on Earth, pushing spacecraft around, etc.

SOLAR PROMINENCE
A solar prominence (also known as a filament) is an arc of gas that erupts from the surface of the Sun. Prominences can loop hundreds of thousands of miles into space. Prominences are held above the Sun's surface by strong magnetic fields and can last for many months. At some time in their existence, most prominences will erupt, spewing enormous amounts of solar material into space.

CORONAL MASS EJECTION
Coronal mass ejections (abbreviated CME's) are huge, balloon-shaped plamsa bursts that come from the Sun. As these bursts of solar wind rise above the Sun's corona, they move along the Sun's magnetic field lines and increase in temperature up to tens of millions of degrees. These bursts release up to 220 billion pounds (100 billion kg) of plasma. CME's can disrupt Earth's satellites. CME's usually happen independently, but are sometimes associated with solar flares.