Coming Around Again (February 2, 2007)
Hi-res TIF image(3.5M)
Sunspots last anywhere from days to months. And the Sun rotates about once every 27-30 days, depending on which latitude one is tracking. Well, over the past 18 days or so, (January 13 - 31, 2006) SOHO observed a good-sized active region (which would be seen as a sunspot group in "normal" white light observing) disappear around the right side of the Sun and be carried around by rotation to re-appear about 13 days later on the left side.
As seen in extreme ultraviolet wavelength of light here (284 Angstroms), these active regions appear as bright areas usually with particles arching along magnetic field lines above them. Active regions and sunspots are areas of intense magnetic activity and the source of much of "space weather" that can affect us here at Earth. As of the end of January the active region seems to be holding together and steadily moving across the face of the Sun. Maybe it'll make all the way around again? Stay tuned...
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.