As the STEREO (Behind) spacecraft observed in extreme UV light, the Sun popped off no fewer than six eruptions over just two days (Aug. 14-15, 2010). At one point, three events were occurring at the same time. Most of these were eruptive prominences in which cooler clouds of gases above the surface break away from the Sun. The most powerful of the events, a coronal mass ejection, began around 6:30 UT on Aug. 15. It was harder to see from this spacecraft’s angle since it blasted out from the whiter active region in the lower center, so it had the Sun as its backdrop.
SOHO Pick of the Week: Popping Out All Over - Credit: SOHO/NASA & ESA
Courtesy of SOHO/STEREO consortium. SOHO is a project of international cooperation between ESA and NASA.
Solar scientists track solar cycles by counting sunspots. Sunspots are caused by magnetic activity that inhibits convection regions forming “colder” areas (roughly 3,000-4,500 K) on Sun’s photosphere. They appear dark only in contrast to the surrounding area (at about 5,780 K). As the Sun’s magnetic field changes over time (back and forth from a maximum to a minimum), the number of sunspots varies. The current solar cycle (24), “officially” began with the appearance of sunspot 981 on January 4, 2008. For almost two years the cycle 24 has been quite boring (the sun has been spotless for about 260 days this year). As the expected increase of solar magnetic activity is about a year overdue, the last week’s appearance of sunspot 1034 and the active sunspot region 1035 (which grew into size of several Earth radii) finally “brightened” things a little.
Sunspot 1034 and Active Sunspot Region 1035 6 times wider than Earth - Credit: SOHO (ESA & NASA)
In the video above, the Michelson Doppler Imager (MDI) aboard the Solar and Heliospheric Observatory (SOHO) captures the appearance of the sunspot region 1035 on December 14, 2009.
Sunspot 1034 and Active Sunspot Region 1035 - Credit: David Evans
