Detection of "invisible sunspots"

Using a new CCD system, we have detected tiny sunspots, which we term "micropores," associated with elements of the magnetic network far from active regions. The smallest micropores detected are less than 1″ in diameter and about half the size of the associated magnetic feature. We find that the pore size is systematically smaller than the size of magnetic element seen in the magnetograms, but the ratio of pore size versus magnetic element size is independent of pore size, suggesting that the difference is real. For the smaller elements there is a good linear relation between the brightness deficit of the pore and the total flux of the magnetic element. The micropores are distinguishable from dark lanes in the granulation by their long life, large brightness deficit, and association with magnetic fields.