  A series of 353 red electronic spectra obtained between 1994 and 2010, and of
171 UBV photometric observations of the 2010 eclipse, were analyzed in an
effort to better understand the eclipsing binary eps Aur. The main results
follow. (1) We attempted to recover a spectrum of the companion by
disentangling the observed spectra of the eps Aur binary failed, but we were
able to disentangle the spectrum of telluric lines and obtain a mean spectrum
of the F-type primary star. The latter was then compared to a grid of synthetic
spectra for a number of plausible values of T(eff) and log(g), but a reasonably
good match was not found. However, we conclude that the observed spectrum is
that of a low-gravity star. (2) We examined changes in the complex H-alpha line
profiles over the past 16 years, with particular emphasis on the 2009-2011
eclipse period, by subtracting a mean out-of-eclipse H-alpha profile
(appropriately shifted in radial velocity) from the observed spectra. We find
that the dark disk around the unseen companion has an extended 'atmosphere'
that manifests itself via blueshifted and redshifted H-alpha 'shell'
absorptions seen projected against the F star. Significantly, the H-alpha shell
line first appeared three years before first contact of the optical eclipse
when the system was not far past maximum separation. (3) Analyses of radial
velocities and central intensities of several strong, unblended spectral lines,
as well as UBV photometry, demonstrated that these observables showed apparent
multiperiodic variability during eclipse. The dominant period of 66.21 was
common to all the observables, but with different phase shifts between these
variables. This result strongly supports our earlier suggestion that the
photometric variability seen during eclipse is intrinsic to the F star, and
therefore, the idea of a central brightening due to a hole in the disk should
be abandoned.
