SDO 12 Years on Orbit, Large Active Region Approaching?

Last week, we celebrated the 12th anniversary of the launch of SDO. This amazing mission is still going strong, measuring the beginnings of Solar Cycle 25 with the same data stream as Solar Cycle 24. The science teams of AIA, HMI, and EVE are one part of the success of SDO. They keep the data flowing to their research, other solar scientists, and the public. Some 440 million images are now stored in the JSOC and EVE SOC!

The Flight Operations Team at Goddard Space Flight Center is another part of SDO’s success. The satellite and ground station are in great shape. FOT members help the science team by planning maneuvers to reduce the of time science data can’t be recorded. They have come to the MOC at odd hours to help resolve a problem and keep the data flowing.

But we shouldn’t forget the final team member, the Sun. And today we can see in the far-side images from February 13, 2022, that a large active region is sitting on the far side of the Sun. We should be seeing it rotate into view about 4 days from today (7 days from February 13). There are at least 4 numbered active regions on the Sun right now. How many will be there next week?

Here is a composite far-side image showing the magnetic field of the near-side (visble disk) of the Sun in greyscale and the time shifts of the far-side in color. A large active region (or sunspot) depresses the surface of the Sun and causes the wave to re-appear earlier than average. We can see a large region on the far-side with τ about -6 seconds.

Far-side images come from analyzing the helioseismic data of HMI and similar instruments. They are useful to watch for active regions developing on the far-side of the Sun where we have little or no other information. Twelve years of HMI data have improved the far-side images, now we will benefit from that work during Solar Cycle 25.

SDO is GO!