Active Region 12192, which was the location of 6 X-class and several M-class flares in late October, is coming back for an encore. Here is a movie of the Sun showing the magnetic field on the side facing the Earth and the farside image from HMI data. It shows the part of the Sun containing AR 12192 rotating back into view, with a large magnetic feature still there.
These composite maps of the Sun’s farside (in yellow) and the line-of-sight magnetic field (blue) show NOAA AR12192 as a bight-dark magnetic feature rotating out of view over the west limb at the beginning, passing the far-side meridian in the middle as a dark area, and approaching the east limb at the end. The farside information is shown as the travel time change in the echo produced by a strong magnetic region.
This farside images allow us to track magnetic features where SDO cannot see. They have been compared with the full-Sun images we make by combining SDO and STEREO images. When AR 12192 returns it will have a new number but we hope it will be just as active.
Many thanks to the HMI team for producing these images and movies. They are available at JSOC.