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Retrieving Solar Images


To discover various characteristics of the Sun, you'll need to observe it. Your "eyes" will be the SOHO spacecraft, currently circling the Sun about 1,000,000 miles from Earth. With SOHO's 12 specialized scientific instruments, we can explore everything from the Sun's glorious halo or "corona", to the violent magnetic storms on its surface, to the sound waves which help us understand the mysteries of the Sun's deep interior.

Using daily pictures collected by the SOHO spacecraft, you are going to observe and record information about the currently visible sunspot groups. What do you think we can learn from watching sunspots?

What You'll Need | What to Do | Getting the Images | Examples | For the Teacher | Exploring Other Images

What You'll Need to Get Started:

  • Sunspot Recording Worksheet.
    Print out and make enough copies for each day of your observations.

  • Latitude/longitude grids.
    Print these out. If you can, copy the grids onto transparency paper.

  • An image of the Sun every day, for about 2 weeks. You will pick these up from the web (see below). Your images will look something like this, only bigger. (The sunspot groups show up as black and white blotches):


What you are going to do:

You are going to observe and track the movement of sunspots (actually, magnetically "active regions") across the Sun's visible disk.
  • Every day, using the web, print out a copy of the internet solar image (we tell you how below). If you don't have a printer, sketch the image and sunspot groups you see. (If you have to sketch, try placing the latitude/longitude grid directly over the image on your screen to find exactly where to sketch your spots. Be careful to always have the image straight up and down.)

  • For each of the major sunspots groups, record on your Sunspot Recording Worksheet:
  • The name of each spot group. Make up any name you want, but make sure to keep track of which group has which name.
  • Where (i.e. at what latitude and longitude) the spot groups lie
  • Note whether there were any observable changes in your sunspot groups (has the group changed size, shape, disappeared altogether?)
  • Collect images every day for 10-14 days. After you've collected your data, go on to the other activities.


Getting the Images:

The images you will be getting are called either intensitygrams or magnetograms. They are retrieved every 96 minutes by the MDI instrument on the SOHO spacecraft.
  • Before going any further, read About the Images. Don't cheat and skip this part!

  • When you look at the image lists, use the images labeled:
    SOHO MDI, Magnetogram, longi. comp., Full Disk
    SOHO MDI, Intensitygram, Full Disk

  • If there is more than one magnetogram or intensitygram available, pick the one done earliest in the day (there will be a time given with each).

SOHO Daily Images


Help-- I Need Some Examples


For the Teacher


Exploring Other Images

There are many interesting sites which provide solar images. The following are particularly good collections of images from various places around the Earth and in space:

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