SUNSPOTTERS
From Satellites: SOHO EIT
Live Data
A complete list of real-time data links is located in the Space Weather Resources section.
The easiest and quickest way to get the EIT images for the current day is to go to the Sun-Earth Viewer. There is a link to the Viewer at the top of this page and there is a link at the top of every page in the Student Observation Network. When you open the Viewer, you will see the page similar to the one below.
The first four images show images from the SOHO EIT instrument (Extreme ultraviolet Imaging Telescope). EIT uses filters to allow the camera to record only particular kinds of ultraviolet light. Ultraviolet light is invisible to our eyes and has no color as we know it. These images are artificially colored to help scientists know what filter was used. The bright spots in these images tell you that there is a lot of this kind of ultraviolet light being emitted. Dark regions show little activity. You should compare these four EIT images to each other and to the SOHO MDI images that shows you where sunspots are. Do the active places (bright spots) in EIT images occur near sunspots?
You can use the controls under the large box on the right to zoom and pan. This feature allows you to see the Sun in great detail. Some small active regions may not be visible until you zoom. The scale under the box on the right compares the size of the Earth with the image. When you click on image #2 it will appear in the large box. When you click on #3, it will appear in the large box. This will allow you to examine each EIT image in detail.
It is important to note that these images are updated about every two hours. However, not all images are updated at the same time. This means that an image might be a few hours before or after others. Also, note that you can download full size images and save them + see instructions under control box.
Another resource for viewing these images together is "The Very Latest SOHO Images" page. Note the date and times on each image.
TEACHER'S NOTE
The EIT images show the solar atmosphere at several wavelengths of ultraviolet light, and therefore, shows solar material at different temperatures. In the images taken at 304 Angstroms (orange image) the bright material is at 60,000 to 80,000 degrees Kelvin. In those taken at 171 Angstroms (blue image), the bright material is at 1 million degrees. 195 Angstrom (green image) images correspond to about 1.5 million Kelvin. 284 Angstrom (yellowish image) images correspond to 2 million degrees. The hotter the temperature, the higher you look in the solar atmosphere. Students may know little about the visible light spectrum and nothing about the rest of the light spectrum that is not visible. The activity, "In a Different Light", is a good unit to broaden student understanding of the visible light spectrum and to introduce them to invisible parts of the spectrum (UV and infrared).
- NASA Official: Dr. James Thieman
- Project Manager: Don Robinson-Boonstra
- Website Manager: Bryan Stephenson