On magnetic measurements in prominences

The successes of magnetic measurements in faint objects located near very bright ones are strongly depending on the stray light in the telescope. We propose a mask with a variable transmission placed on the primary optics of a telescope. Our computations of the stray light in such a telescope indicate that the calculated coronagraphic factor of improvement, K, would increase at least by 2 orders of magnitude compared to the Lyot-type coronagraph.