STEREO - Solar Terrestrial Relations Observatory
[Home] [Contact] [Site Map]

Important notice about STEREO Behind

Near Record Quiet


The Sun had no sunspots for 51 days in a row from July 11 – Aug. 30, 2009 -- just nearly breaking the record (52 days) for the longest quiet period of this solar cycle set last summer. As we watch 50 days of that period with STEREO (Behind) in extreme UV light, we see some activity, such as prominences popping up, but no active regions strong enough to form a sunspot. On Aug. 31, a little sunspot emerged (not shown in the clip) to interrupt the long string of quiet days. Nevertheless, it is likely that the current year’s number of blank days will be the longest in about 100 years.

Last Revised: March 19, 2018 15:00:39 UTC
Responsible NASA Official:
Privacy Policy and Important Notices
Webmaster: Kevin Addison