Eclipse mapping of the hot circumstellar plasma in Algol binaries

Phase‐resolved FUV observations of three Algol‐type interacting binaries (V356 Sgr, TT Hya, and RY Per) have been made during totality with the Far Ultraviolet Spectroscopic Explorer to map the location of the hot circumstellar plasma that produces emission lines of O VI, Si III,IV, S IV, C III, and N II. Since OVI shows very little variation in profile, strength, and velocity as the disk of the secondary occults the line formation region, we conclude that the emission originates in material that has a substantial flow perpendicular to the orbital plane (perhaps a bipolar jet). The behavior of the emission lines from the moderate‐ionization species suggests that the plasma producing these emission features has a large equatorial component. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)