CWL

A Year on the Sun

Our solar system’s miasma of incandescent plasma, the Sun may look a little scary here.

The picture is a composite of 25 images recorded in extreme ultraviolet light by the orbiting Solar Dynamics Observatory between April 16, 2012 and April 15, 2013. The particular wavelength of light, 171 angstroms, shows emission from highly ionized iron atoms in the solar corona at a characteristic temperatures of about 600,000 kelvins (about 1 million degrees F).

Girdling both sides of the equator during the approach to maximum in its 11-year solar cycle, the solar active regions are laced with bright loops and arcs along magnetic field lines. Of course, a more familiar visible light view would show the bright active regions as groups of dark sunspots. Three years of Solar Dynamics Observatory images are compressed into this short video.

Graceful Eruption

A solar prominence began to bow out and the broke apart in a graceful, floating style during a little less than four hours (Mar. 16, 2013).

The sequence was captured in extreme ultraviolet light.

A large cloud of the particles appeared to hover further out above the surface before it faded away.

Credit: Solar Dynamics Observatory/NASA

NASA’s Solar Dynamics Observatory captured this image of an M6.5 class flare at 3:16 EDT on April 11, 2013. This image shows a combination of light in wavelengths of 131 and 171 Angstroms. Credit: NASA/SDO

Erratic Tug of War

Solar plasma, darker than the bright, magnetic loops that serve as its background, serves up an intricate tug of war over about 18 hours just above the Sun’s surface (Mar. 28-29, 2013).

The plasma is tugged back and forth as competing magnetic forces pull at it. This material appears darker since it is cooler than the surrounding material.

About mid-way through the video clip, a burst of plasma in the foreground seems to leap out and dive towards an active region closer to the viewer. The superb level of details, such as the kind shown here, could never be observed before SDO began its operations.

In the Loops

A pair of solar active regions spun up dozens of arching loops above them and extending an estimated 100,000 miles between them as they rotated into view over the period of one day (Mar. 26-27, 2013).

Active regions are areas of intense magnetic forces pushing up from beneath the solar surface. The loops are charged particles spinning along the magnetic field lines as observed in extreme ultraviolet light. Active regions are often the sources of solar storms, so we will be keeping our eye on them.

Flux Ropes on the Sun

NASA IOTD | 2013 Feb 15

This is an image of magnetic loops on the sun, captured by NASA’s Solar Dynamics Observatory (SDO). It has been processed to highlight the edges of each loop to make the structure more clear.

A series of loops such as this is known as a flux rope, and these lie at the heart of eruptions on the sun known as coronal mass ejections (CMEs.) This is the first time scientists were able to discern the timing of a flux rope’s formation. (Blended 131 Angstrom and 171 Angstrom images of July 19, 2012 flare and CME.)

Image Credit: NASA/GSFC/SDO

Making the Rounds

Early on Jan. 31, 2013, SDO observed a visual phenomena that most of us do not recall ever seeing before: a ring-shaped prominence that lay flat above the Sun’s surface.

Plasma streaming along the magnetic field lines appears to go in both directions at the same time along the field lines. Before long, the prominence became unstable and erupted in a large swirl with most of the materials falling back into the Sun. You never know what you are going to see next.

Double Prominence Eruptions

The Sun erupted with two prominence eruptions, one after the other over a four-hour period (Nov. 16, 2012).

The action was captured in the 304 Angstrom wavelength of extreme ultraviolet light. It seems possible that the disruption to the Sun’s magnetic field might have triggered the second event since they were in relatively close proximity to each other. The expanding particle clouds heading into space do not appear to be Earth-directed.

Graceful Streaming

Streaming plasma rather gracefully traced magnetic field lines above an active region over a two-day period (Oct. 23-25, 2012).

This close up presents a nice profile of the activity in the 304 Angstrom wavelength of extreme ultraviolet light. Right after the video clip begins a solar flare erupts in a bright flash from the active region (whiter area) to the right of the arcing plasma. The darker red strand angling upwards from the lower part of the Sun is a solar pominence.

X 1.2 Flare

The Sun emitted a significant solar flare on Oct. 22, 2012, peaking at 11:17 p.m. EDT. The flare came from an active region on the left side of the sun that has been numbered AR 1598, which has already been the source of a number of weaker flares. It was captured by SDO in the 131 Angstrom wavelength of extreme ultraviolet light. The movies covers less than an hour.

This flare was classified as an X.1-class flare. “X-class” denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, and so on. An X-class flare of this intensity can cause degradation or blackouts of radio communications for about an hour. This event did produce an impulsive R3 Solar Flare Radio Blackout. R3 is considered “Strong”, meaning a wide area blackout of HF radio communication, loss of radio contact for about an hour on the sunlit side of Earth.

Major Solar Flare Erupts From the Sun

The sun unleashed a powerful solar flare late Monday (Oct. 22), releasing waves of radiation into space that have already caused a short radio blackout on Earth.

The flare erupted from the sunspot AR 11598 (short for Active Region 11598), and reached peak brightness at 11:22 p.m. EDT (0322 GMT this morning, Oct. 23), according to scientists working on NASA’s Solar Dynamics Observatory (SDO), a space telescope that constantly monitors the sun with high-definition cameras. It ranked as an X1.8 solar flare, one of the strongest types of solar flares, according to the U.S. Space Weather Prediction Center (SWPC) run by NOAA and the National Weather Service.

The same sunspot produced three strong flares before this one in just the two days since it became visible from Earth’s perspective. “This means more flares are probably in the offing, and they will become increasingly Earth-directed as the sunspot turns toward our planet in the days ahead,” astronomer Tony Phillips wrote on Spaceweather.com, a website that tracks skywatching and space weather events.

Proliferating Loops

Dozens of loops gyrated above several active regions as they were rotating into view (Oct. 13-17, 2012).

When viewed in extreme ultraviolet light, the dancing loops of competing and connecting magnetic field lines become visible. Two minor eruptions can be observed at the upper left area.

Fore-Warnings

This dynamic active region, which has already popped off 12 flares (C and M class) in just two days (Oct. 8-10, 2012), is rotating into view.

The region may be a harbinger of geo-effective activity to come. This wavelength of extreme ultraviolet light (131 Angstrom) can observe plasma at temperatures up to 10 million degrees. Another active region above this one is also quite large and could also produce some major solar storms.

The March Towards Max

These six images from SDO, chosen to show a representative image about every six months, track the rising level of solar activity since the mission first began to produce consistent images in May, 2010. The period of solar maximum is expected in 2013. The images were taken in the 171 Angstrom wavelength of extreme ultraviolet light.