Active region NOAA AR 8194

This picture of the active region NOAA AR 8194 shows seismic images just before (left frame) and during (center) its passage across the far-side solar meridian, on 27 and 28 March 1998, respectively. The right frame shows an NSO/Kitt Peak magnetogram of AR 8194 ten days later, when the region has passed onto the visible disk of the Sun. See the article in the NOAO June 2000 newsletter.