What Lies Beneath (April 28, 2006)
Hi-res TIF image
In an image that captured features just above the Sun's surface in extreme UV light this past week (April 26, 2006), we saw two groups of medium-sized sunspots that appeared as distinctly lighter areas on the surface. These are the sites of intense magnetic fields emerging from the Sun's interior. But, with another instrument on SOHO, we can also peel down further and detect on the surface what the Sun is doing magnetically at just about the same time.
The magnetic image (in black and white and called a magnetogram) reveals the sunspots as clusters of magnetic activity, with the paired black and white areas indicating north and south magnetic polarity. Note the very close correlation of active regions in one and magnetic pairings in the other. The magnetically active regions in which sunspots are found are often the sources of solar storms. We'll watch and see how these active regions develop over the next week or so.
The Sun is producing far fewer CMEs than we have been used to observing in the past years because the Sun is nearing its period of minimum activity. There are fewer active regions and fewer sunspots as well.
SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.
If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to firstname.lastname@example.org.