O I $\lambda$7774 Absorption as a Tracer of Streams and Disks in Non-Degenerate Binary Stars
Session 85 -- Binaries
Display presentation, Wednesday, 11, 1995, 9:20am - 6:30pm

## [85.03] O I $\lambda$7774 Absorption as a Tracer of Streams and Disks in Non-Degenerate Binary Stars

P.B. Etzel (SDSU), E.C. Olson (UIUC), M.C. Senay (IfA/Hawaii)

We proprose a new spectroscopic approach for observing circumstellar matter in binary stars, based on the neutral oxygen $\lambda$7774 absorption lines. We present oxygen equivalent widths and radial velocities in 20 non-degenerate eclipsing binaries. We note limitations and advantages of using this line to trace circumstellar matter in binary systems, and confirm the presence of streams and rotating accretion disks in a number of short- and long-period Algol systems. We discuss evidence for geometrically thick disks, and describe a small radial in-fall superimposed on disk rotation in most long-period systems. We speculate that in-fall may be related to viscous dissipation in disks. We emphasize the great sensitivity of $\lambda$7774 in studying the kinematics of circumstellar matter in many non-degenerate binaries.