Various methods outlined for indirect planetary detection would greatly benefit (in some cases require) the determination of the planetary orbital plane, which is theoretically equivalent to the stellar equatorial plane. Determining the stellar space orientation, therefore, would greatly benefit extrasolar planetary detection.
We utilize stellar rotation periods determined from short-term variations in Call H&K sunspot emission combined with both stellar radii measurements and Doppler broadened spectral line profiles to get the stellar inclination to the line of sight.
The clocklike, on the plane-of-the-sky component determination utilizes the concentration of sunspot associated plage areas at central stellar latitudes when viewed in Call H or K emission. One can perform Call H&K emission speckle interferometry to measure the clocklike angle of this stellar Call H&K emission band, modeling it as an elliptical intensity distribution. Both components should be determinable to within ten degrees for at least resolvable fifth magnitude stars.