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Session 43 - Binary Stars.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center
Preliminary analysis of the eclipsing binary V342 Aquilae indicates it is undergoing an extremely active phase of mass flow. Three observational datasets provide complete orbital phase coverage of the 3.39 day period across a wide band; IUE spectroscopic data, photometric uvbyRI data, and optical spectroscopy data. IUE observations made in 1991, 1993 and 1995 include 88 low resolution SWP and LWP spectra spanning from 1150 to 3200 ÅThe uvbyRI optical photometry data (P. Etzel) were obtained simultaneously with the 1993 IUE observations. Limited KPNO 2.1 meter telescope optical data (A. Welty) covering from 3840 to 9000 Åwere taken in 1994. Our UV spectra show very pronounced Fe II absorption lines arising from ground and metastable levels, indicating an extensive circumstellar shell in the system. The strength of this absorption shows both an orbital and a cycle-to-cycle variability. The eclipse spectra display very strong emission from lines such as C II at 1335 ÅSi IV at 1400 Åand C IV at 1550 Åwith a striking similarity to the eclipse spectra of TT Hydrae. Based upon these data, we have deduced the effective temperatures, spectral types and orbital geometry of the two stars. The UV spectra show the primary is approximately a late B star and the secondary is a late G star. We also present velocity curve results from the optical data along with the resulting mass ratio estimate. Our ongoing analysis aims to understand the unusually large rate of mass flow occuring in V342 Aquilae.
P.B.E. acknowledges support under NSF grant AST-9115104.
Program listing for Tuesday