The detection and nature of a 'speckle astrometric' system are reported with attention given to alternative interpretations of the system components. The HR 226 = ADS 784 system is described as a short-period binary (with a period of 4.241148 +/- 0.000008 d) orbiting an unseen companion (with a period of 1769 +/- 10 d), and the triple's visual orbit is 83.10 +/- 0.20 yr. The elements of the various orbits taken from spectroscopic data are employed to develop the model scenarios. The masses and spectral types of the components are developed and used to calculate the inclinations of the short-, intermediate-, and long-period orbits. The computations show that the inclinations are similar and can be interpreted as three coplanar orbits; however, this conclusion suggests that the unseen companion's absorption features should be detectable. Since the absorption features are not detectable it is concluded that the unseen companion is either a pair of late-type lower-mass stars or one rapidly rotating star.
Cole, W.A.; Fekel, F.C.; Hartkopf, W.I.; McAlister, H.A.; Tomkin, J. "HR 266=ADS 784: an Early Type Spectroscopic, Speckle Astrometric Multiple System" Astronomical Journal v.103, p.1357 (1992)