THE ASTROPHYSICAL JOURNAL, 484:394-411, 1997 July 20

                      NEW PERSPECTIVES ON AX MONOCEROTIS

         NICHOLAS M. ELIAS II[1], R.E. WILSON[2], EDWARD C. OLSON[3],
        JASON P. AUFDENBERG[4], EDWARD F. GUINAN[5], MANUAL GUEDEL[6],
               WALTER V. VAN HAMME[7], AND HEATHER L. STEVENS[8]


                                   ABSTRACT

        AX Monocerotis is a 232 d, noneclipsing, interacting binary star
     that consists of a K giant, a Be-like giant, and a large amounts of
     circumstellar material.  The K star is almost certainly a synchronous
     rotator and is probably in contact with its critical lobe.  The Be
     star was believed to be a rapid rotator based on extremely wide
     absorption lines, but new spectra show that these lines arise from the
     circumstellar environment.  Hydrogen emission, also circumstellar, is
     many times stronger than the continuum.  Near-ultraviolet light curves
     exhibit a 0.5 mag dip near phase 0.75, but there is no such
     variability at longer wavelengths.  Gas flow trajectories from the
     cusp of the K star roward the Be star provide a simple explanation for
     the photometric and spectroscopic behavior.  We may have found a
     decreasing orbital period, but more data 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.  Further observations,
     including optical interferometry, are proposed.

     Subject headings: binaries: spectroscopic -- circumstellar matter --
                       radio continuum: stars -- stars: emission-line, Be --
                       stars: individual (AX Monocerotis) --
                       ultraviolet: stars

     1 United States Naval Observatory, Astrometry Department, USNO/NRL
     Optical Interferometer Project, 3450 Massachusetts Avenue NW,
     Washington, DC 20392-5420; nme@fornax.usno.navy.mil.

     2 University of Florida, Astronomy Department, SSRB, Gainseville, FL
     32611.

     3 University of Illinois, Urbana-Champaign, Astronomy Department, 1002
     West Green Street, Urbana, IL 61801; olsomed@sirius.astro.uiuc.edu.

     4 Arizona State University, Physics and Astronomy, Box 871504, Tempe,
     AZ 85781-1504; jaufdenb@sara.la.asu.edu.

     5 Astronomy Department, Villanova University, Villanova, PA 19085;
     guinan@ucis.vill.edu.

     6 Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland;
     guedel@astro.phys.ethz.ch.

     7 Forida International University, Department of Physics, University
     Park, Miami, FL 33199; vanhamme@jove.fiu.edu.

     8 University of Virginia, Department of Political and Social Thought,
     Cabell 232, Charlottesville, VA 22903; hls3e@uva.pcmail.virginia.edu.