R-AQUARII - H-ALPHA MAP OF SUBARCSECOND INNER STRUCTURE

A 45 mas resolution image of R Aqr, observed near minimum brightness with speckle interferometry in a 1.8 nm optical bandpass centered on H-alpha, was obtained with the NOAO 4 m Mayall telescope at Kitt Peak. We resolved three H-alpha sources: (1) a bright central H-alpha source which has a 2 cm counterpart previously designated C1 and probably arising from a hot companion and its accretion disk as they orbit a long-period variable (LPV); (2) a approximately 3.3 mag fainter H-alpha source lying approximately 0".53 along p.a. approximately 46.30-degrees relative to C1, corresponding to C2 in 2 cm continuum; the flux ratio of C1 to C2 in H-alpha is 18:1 compared to 6:1 in 2 cm continuum; and (3) a approximately 2.4 mag fainter H-alpha source lying approximately 0."124 along p.a. approximately 226.40-degrees relative to C1; this source has no radio counterpart, and we designate it C3. The H-alpha C1-C3 separation is consistent with the separation between the close proximity astrometric positions of the LPV and SiO maser sources and the absolute position of the C1 radio component seen in high resolution with the VLA. Moreover, the C1-C3 axis is remarkably well aligned with the symmetric inner jet seen in [O III] at 5007 angstrom. While the nature of C3 is not known at present, it may arise in the LPV envelope or could simply be another knot of emission in the inner jet. If C3 is in fact associated with the LPV at 180 pc, it would be the first spatial resolution of the stellar components of the system as the C1-C3 distance is approximately 3.3 x 10(14) cm and on the order of the binary separation previously suspended for the system.