NEW PERSPECTIVES ON AX MONOCEROTIS

AX Moncerotis is a 232(d), noneclipsing, interacting binary star that consists of a K giant, a Be-like giant, and large amounts of circumste llar material. The K star is almost certainly a synchronous rotator an d is probably in contact with its critical lobe. The Be star was belie ved to be a rapid rotator based on extremely wide absorption lines, bu t new spectra show that these lines arise from the circumstellar envir onment. Hydrogen emission, also circumstellar, is many times stronger than the continuum. Near-ultraviolet light curves exhibit a 0.5 mag di p near phase 0.75, but there is no such variability at longer waveleng ths. Gas flow trajectories from the cusp of the K star toward the Be s tar provide a simple explanation for the photometric and spectroscopic behavior. We may have found a decreasing orbital period, but more dat a are necessary to confirm this result. We present several models for AX Mon based on (1) new and archival visible photometry, (2) archival ultraviolet spectroscopy, (3) new and archival visible spectroscopy, ( 4) new visible polarimetry, and (5) new radio photometry. Future obser vations, including optical interferometry, are proposed.