SDO: Visualizations

Argos (or Argus Panoptes) was the 100-eyed giant in Greek mythology (wikipedia).

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.

Argos (or Argus Panoptes) was the 100-eyed giant in Greek mythology (wikipedia).

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.

Our sun is ever-changing, and the Solar Dynamics Observatory has a front-row seat. On Feb. 11, 2010, NASA launched the Solar Dynamics Observatory, also known as SDO. SDO keeps a constant eye on the sun, helping us track everything from sunspots to solar flares to other types of space weather that can have an impact on Earth. For instance, solar activity is behind the aurora, one of Earth’s most dazzling natural events. The sun’s activity rises and falls in a pattern that lasts about 11 years on average. This is called the solar cycle. After seven years in space, SDO has had a chance to do what few other satellites have been able to do – watch the sun for the majority of a solar cycle in 11 types of light. This video shows two.

The large active region AR12192 is carried across the solar disk by the Sun's rotation. The region erupted with a large number of M and an X-class flares. Flare classification is defined by the measured X-ray flux from a detector on the GOES satellites (see Classifying Solar Eruptions). This visualization was the result of some experiments to present both the SDO imagery and GOES X-ray flux as part of a single movie.

To improve our understanding of complex phenomena such as solar flares, a wide variety of tools are needed. In the case of astronomy, those tools enable us to analyze the light in many different wavelengths and many different ways. Many different instruments are observing the Sun almost continuously, both from space and on the surface of the Earth. On March 29, 2014, the Dunn Solar Telescope at Sacramento Peak, New Mexico was observing a solar active region and requested other observatories to watch as well. As a result of this coordination, the region was being observed by a large number of different instruments, ground and space-based, when it subsequently erupted with an X-class flare. This visualization presents various combinations of the datasets collected during this effort. The color text represents the dominant color of the dataset in the imagery.

The Solar Dynamics Observatory (SDO) observes the Sun with many different instruments, in many different wavelengths of light. Many of these capabilities are not possible for ground-based observatories - hence the need for a space-based observing platform.

The Extreme Ultraviolet (EUV) Variability Experiment (EVE) measures extreme ultraviolet emission from the solar chromosphere, transition region and corona. This radiation is mostly absorbed in Earth's upper atmosphere and influences Earth's climate.

This visualization is one of a set of visualizations (others linked below) covering the same time span of 17 hours over the full wavelength range of the mission. They are setup to play synchronously on a Hyperwall, or can be run individually.

The images are sampled every 36 seconds, 1/3 of the standard time-cadence for SDO. This visualization is useful for illustrating how different solar phenomena, such as sunspots and active regions, look very different in different wavelengths of light. This differences enable scientists to study them more completely, with an eventual goal of improving Space Weather forecasting.

The Solar Dynamics Observatory (SDO) observes the Sun with many different instruments, in many different wavelengths of light. Many of these capabilities are not possible for ground-based observatories - hence the need for a space-based observing platform.

The Helioseismic Magnetic Imager (HMI) aboard the Solar Dynamics Observatory takes a series of images every 45 seconds in a very narrow range of wavelengths in visible light of the solar photosphere. The wavelengths correspond to a region around the 6173 Ångstroms (617.3 nanometers) spectral line of neutral iron (Fe I). From this series of images, it constructs a set of images which extract other characteristics of the photosphere. For this dataset, it measures the shifting of the spectral lines to determine the velocity of gas flows on the solar surface. This spectral line shift is due to the Doppler effect (Wikipedia). Blue represents motion towards the observer. Red indicates motion away from the observer.

For the images below, the color is dominated by the solar rotation, so the solar limb on the right is moving away from us (and therefore red) while the left limb is moving towards us (and therefore blue). Motions on the solar surface generate the rippling in the color and you can see evidence of surface flows around the sunspot near the left limb.

This visualization is one of a set of visualizations (others linked below) covering the same time span of 17 hours over the full wavelength range of the mission. They are setup to play synchronously on a Hyperwall, or can be run individually.

The images are sampled every 36 seconds, 1/3 of the standard time-cadence for SDO. This visualization is useful for illustrating how different solar phenomena, such as sunspots and active regions, look very different in different wavelengths of light. These differences enable scientists to study them more completely, with an eventual goal of improving Space Weather forecasting.

This is a sequence of 4Kx2K images, cylindrical-equidistant projection, of the Sun that can be mapped to a sphere. The sequence was assembled by combining 304 Ångstrom (extreme ultraviolet wavelength) images from STEREO-A, STEREO-B, and the Solar Dynamics Observatory (SDO). The series covers the time frame shortly after the STEREO spacecraft moved into a position where they had a complete view of the side of the Sun not visible from the Earth (see Sun 360).

Technical Details

The data are sampled in time approximately every three hours. Since each spacecraft is at a slightly different distance from the Sun, the intensity received by each pixel was normalized to correspond to the intensity one astronomical unit from the Sun using the inverse-square law. The flux was also adjusted for the fact that each pixel captures a different fraction of the light due to their different angular size for each spacecraft. The image from each spacecraft is then reprojected using the World Coordinate System (WCS) routines of the SolarSoft library. Masks were made to smooth the transition where datasets overlap. There are a few gaps in the data, especially near the poles of the Sun, that are filled using data from the previous time step.

Note: This sequence is suitable for animation and visualization purposes but NOT for scientific analysis.