SDO: Presentation Resources

The data is plotted in Carrington coordinates which are "fixed" to the surface of the Sun. In this coordinate system, the active regions tend to stay at the same location. However, the Sun's rotation rate actually changes with latitude and this can be seen in the movie.

Used in 2014 Calendar.

Although Mercury zooms around the sun every 88 days, Earth, the sun and Mercury rarely align. And because Mercury orbits in a plane that is tilted from Earth’s orbit, it usually moves above or below our line of sight to the sun.

Transits provide a great opportunity to study the way planets and stars move in space—information that has been used throughout the ages to better understand the solar system and which still helps scientists today calibrate their instruments.

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=90796

While the Solar Dynamics Observatory (SDO) has significantly less than 100 eyes, (see "SDO Jewelbox: The Many Eyes of SDO"), seeing connections in the solar atmosphere through the many filters of SDO presents a number of interesting challenges. This visualization experiment illustrates a mechanism for highlighting these connections.

The wavelengths presented are: 617.3nm optical light from SDO/HMI. From SDO/AIA we have 170nm (pink), then 160nm (green), 33.5nm (blue), 30.4nm (orange), 21.1nm (violet), 19.3nm (bronze), 17.1nm (gold), 13.1nm (aqua) and 9.4nm (green).

We've locked the camera to rotate the view of the Sun so each wedge-shaped wavelength filter passes over a region of the Sun. As the features pass from one wavelength to the next, we can see dramatic differences in solar structures that appear in different wavelengths.

• Filaments extending off the limb of the Sun which are bright in 30.4 nanometers, appear dark in many other wavelengths.
• Sunspots which appear dark in optical wavelengths, are festooned with glowing ribbons in ultraviolet wavelengths.
• Small flares, invisible in optical wavelengths, are bright ribbons in ultraviolet wavelengths.
• If we compare the visible light limb of the Sun with the 170 nanometer filter on the left, with the visible light limb and the 9.4 nanometer filter on the right, we see that the 'edge' is at different heights. This effect is due to the different amounts of absorption, and emission, of the solar atmosphere in ultraviolet light.
• In far ultraviolet light, the photosphere is dark since the black-body spectrum at a temperature of 5700 Kelvin emits very little light in this wavelength.

While the Solar Dynamics Observatory (SDO) has significantly less than 100 eyes, (see "SDO Jewelbox: The Many Eyes of SDO"), seeing connections in the solar atmosphere through the many filters of SDO presents a number of interesting challenges. This visualization experiment illustrates a mechanism for highlighting these connections.

This visualization is a variation of the original Solar Dynamics Observatory - Argo view. In this case, the different wavelength filters are presented in three sets around the Sun at full 4Kx4K resolution. This enables monitoring of changes in time over all wavelengths at any location around the limb of the Sun.

The wavelengths presented are: 617.3nm optical light from SDO/HMI. From SDO/AIA we have 170nm (pink), then 160nm (green), 33.5nm (blue), 30.4nm (orange), 21.1nm (violet), 19.3nm (bronze), 17.1nm (gold), 13.1nm (aqua) and 9.4nm (green).

We've locked the camera to rotate the view of the Sun so each wedge-shaped wavelength filter passes over a region of the Sun. As the features pass from one wavelength to the next, we can see dramatic differences in solar structures that appear in different wavelengths.

• Filaments extending off the limb of the Sun which are bright in 30.4 nanometers, appear dark in many other wavelengths.
• Sunspots which appear dark in optical wavelengths, are festooned with glowing ribbons in ultraviolet wavelengths.
• small flares, invisible in optical wavelengths, are bright ribbons in ultraviolet wavelengths.
• if we compare the visible light limb of the Sun with the 170 nanometer filter on the left, with the visible light limb and the 9.4 nanometer filter on the right, we see that the 'edge' is at different heights. This effect is due to the different amounts of absorption, and emission, of the solar atmosphere in ultraviolet light.
• in far ultraviolet light, the photosphere is dark since the black-body spectrum at a temperature of 5700 Kelvin emits very little light in this wavelength.

The primary feature of interest was the whirrling tower of plasma on the lower right limb.

10-HMI Magnetogram; 9-AIA 4500; 8-AIA 094; 7-HMI Dopplergram; 6-AIA 171; 5-AIA 171-211-304; 4-AIA 171-211-304; 3-AIA 304; 2-AIA 304; 1-AIA 304

The last 5 seconds of countdown show the large prominence eruption that occured March 30, 2010, just after SDO's sensors were turned on.

Yellow light of 5800 angstroms, for example, generally emanates from material of about 10,000 degrees F (5700 degrees C), which represents the surface of the sun. Extreme ultraviolet light of 94 angstroms, on the other hand, comes from atoms that are about 11 million degrees F (6,300,000 degrees C) and is a good wavelength for looking at solar flares, which can reach such high temperatures. By examining pictures of the sun in a variety of wavelengths — as is done through such telescopes as NASA's Solar Dynamics Observatory (SDO), NASA's Solar Terrestrial Relations Observatory (STEREO) and the ESA/NASA Solar and Heliospheric Observatory (SOHO) — scientists can track how particles and heat move through the sun's atmosphere.

We see the visible spectrum of light simply because the sun is made up of a hot gas — heat produces light just as it does in an incandescent light bulb. But when it comes to the shorter wavelengths, the sun sends out extreme ultraviolet light and x-rays because it is filled with many kinds of atoms, each of which give off light of a certain wavelength when they reach a certain temperature. Not only does the sun contain many different atoms — helium, hydrogen, iron, for example — but also different kinds of each atom with different electrical charges, known as ions. Each ion can emit light at specific wavelengths when it reaches a particular temperature. Scientists have cataloged which atoms produce which wavelengths since the early 1900s, and the associations are well documented in lists that can take up hundreds of pages.

Instruments that produce conventional images of the sun focus exclusively on light around one particular wavelength, sometimes not one that is visible to the naked eye. SDO scientists, for example, chose 10 different wavelengths to observe for its Atmospheric Imaging Assembly (AIA) instrument. Each wavelength is largely based on a single, or perhaps two types of ions — though slightly longer and shorter wavelengths produced by other ions are also invariably part of the picture. Each wavelength was chosen to highlight a particular part of the sun's atmosphere.

From the sun's surface on out, the wavelengths SDO observes, measured in angstroms, are:

4500: Showing the sun's surface or photosphere.

1700: Shows surface of the sun, as well as a layer of the sun's atmosphere called the chromosphere, which lies just above the photosphere and is where the temperature begins rising.

1600: Shows a mixture between the upper photosphere and what's called the transition region, a region between the chromosphere and the upper most layer of the sun's atmosphere called the corona. The transition region is where the temperature rapidly rises.

304: This light is emitted from the chromosphere and transition region.

171: This wavelength shows the sun's atmosphere, or corona, when it's quiet. It also shows giant magnetic arcs known as coronal loops.

193: Shows a slightly hotter region of the corona, and also the much hotter material of a solar flare.

211: This wavelength shows hotter, magnetically active regions in the sun's corona.

335: This wavelength also shows hotter, magnetically active regions in the corona.

94: This highlights regions of the corona during a solar flare.

131: The hottest material in a flare.

Eight hours later, on July 19, the same region flared again. This time the flux rope's connection to the sun was severed, and the magnetic fields escaped into space, dragging billions of tons of solar material along for the ride — a classic CME.

More than just gorgeous to see, such direct observation offers one case study on how this crucial kernel at the heart of a CME forms. Such flux ropes have been seen in images of CMEs as they fly away from the sun, but it's never been known — indeed, has been strongly debated — whether the flux rope formed before or in conjunction with a CME's launch. This case shows a clear-cut example of the flux rope forming ahead of time.

SDO's Atmospheric Imaging Assembly (AIA) captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 Kelvin. In this wavelength it is easy to see the sun's 25-day rotation as well as how solar activity has increased over three years.

During the course of the video, the sun subtly increases and decreases in apparent size. This is because the distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits the Earth at 6,876 miles per hour and the Earth orbits the sun at 67,062 miles per hour.

Such stability is crucial for scientists, who use SDO to learn more about our closest star. These images have regularly caught solar flares and coronal mass ejections in the act, types of space weather that can send radiation and solar material toward Earth and interfere with satellites in space. SDO's glimpses into the violent dance on the sun help scientists understand what causes these giant explosions — with the hopes of some day improving our ability to predict this space weather.

The four wavelength view at the end of the video shows light at 4500 angstroms, which is basically the visible light view of the sun, and reveals sunspots; light at 193 angstroms which highlights material at 1 million Kelvin and reveals more of the sun's corona; light at 304 angstroms which highlights material at around 50,000 Kelvin and shows features in the transition region and chromosphere of the sun; and light at 171 angstroms.

Noteworthy events that appear briefly in the main sequence of this video:

00:30;24 Partial eclipse by the moon

If one looks closely at such a crisp border, the features of the moon’s topography are visible, as is the case in this image from Oct. 7, 2010. This recently inspired two NASA visualizers to overlay a 3-dimensional model of the moon based on data from NASA’s Lunar Reconnaissance Orbiter into the shadow of the SDO image. Such a task is fairly tricky, as the visualizers — Scott Wiessinger who typically works with the SDO imagery and Ernie Wright who works with the LRO imagery — had to precisely match up data from the correct time and viewpoint for the two separate instruments. The end result is an awe-inspiring image of the sun and the moon.

To start the process, the visualizers took the viewing position and time from the SDO image. This information was dropped into an LRO model that can produce the exact view of the moon from anywhere, at any time, by incorporating 6 billion individual measurements of the moon’s surface height from LRO’s Lunar Orbiter Laser Altimeter instrument. The model had to take many factors into consideration, including not only SDO’s distance and viewing angle, but also the moon’s rotation and constant motion. Wright used animation software to wrap the elevation and appearance map around a sphere to simulate the moon.

The two images were put together and the overlay was exact. The mountains and valleys on the horizon of the LRO picture fit right into the shadows seen by SDO.

In its own way, this served as a kind of calibration of data. It means that the SDO data on its position and time is highly accurate and that the LRO models, too, are able to accurately provide images of what’s happening at any given moment in time.

And of course, the whole exercise provides for a beautiful picture.

To have a record of such an intense flare from so many observatories is unprecedented. Such research can help scientists better understand what catalyst sets off these large explosions on the sun. Perhaps we may even some day be able to predict their onset and forewarn of the radio blackouts solar flares can cause near Earth – blackouts that can interfere with airplane, ship and military communications.