Pick of The Week

"Backward" Sunspot? (September 1, 2006)

Hi-res TIF image(2.2M)

The sunspot at Active Region 905 is raising eyebrows among scientists and sunspot followers in general. It is being speculated that the magnetic orientation of this spot is the reverse of what we have been observing during the current solar cycle. Sunspots are areas of intense magnetic activity and occur in pairs with a north and south polarity, just as a magnet does.

During the current 11-year solar cycle, which is nearing its end, the sunspots have had the north pole on the left and the south on the right. This sunspot, and a smaller and short-lived one last in July, apparenttly have the orientation reversed as seen in the magnetic image of the sunspot above. If so, this would most likely signal the beginning of the next solar cycle, one that is predicted to be 30-50% more intense than the last one.

However, for a number of reasons, the jury is still out. For one thing, the spot is less than 10 degrees south of the solar equator and history has shown that sunspots of a new cycle usually appear at about 25 degrees from the equator. Also, the two spots are quite far apart though they seem to be connected to each other. Finally, graphs of the solar cycle strongly suggest that the current solar cycle has not reached its bottom plateau yet. And no scientists have predicted that the next cycle would begin this early.

So, SOHO scientists, at least, are taking a cautious wait and see attitude. This is science: making observations, assessing all the facts, and trying to decide if there is sufficient evidence to draw a reasonable conclusion. Though the spot is interesting and unusual, SOHO scientists are scratching their heads trying to decide if this region really is the first large one of the new cycle. Stay tuned.

Previous Picks of the Week

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 steele.hill@gsfc.nasa.gov.


• European Site • US Site


Feedback & Comments: SOHO Webmaster

Last modification:

SOHO is a project of international cooperation between