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VV Cephei (= HR 8383 = HD 208816) is the brightest eclipsing M supergiant binary (M2 Iab + B0-2? V) in the sky, and is a massive binary with one of the longest known orbital periods (7430 days = 20.34 years) of any eclipsing system. With the next eclipse beginning in August 2017, and lasting nearly two years (650 days) from 1st to 4th contact, an extensive observational campaign is planned. This paper focusses on the photometric variability of the system out of eclipse, and presents and photometry and H emission fluxes observed over the period from mid-2008 through late 2016. The and light curves show correlated variability with peak power of 145 days, presumably due to low-amplitude pulsations of the M supergiant. The H emission fluxes show a short-term variability, but the sampling is not sufficient to permit quantitative analysis. However, the H fluxes also appear to show a long-term modulation related to the variable orbital separation of this eccentric binary.

We examine the little-known phenomenon of orbitally modulated Si i emission at λ 3905.523 Å and λ 4102.936 Å in composite-spectrum binaries, with specific reference to ζ Aurigae (K4 Ib + B5 V). The emission is detected in the isolated spectrum of the B-type dwarf secondary, and while λ 4102 Å is heavily blended with Hδ, λ 3905 Å falls in the B-star's featureless continuum. The narrowness of the emission (vturb ≃ 6 km s−1) demonstrates that it originates in the upper photosphere or deep chromosphere of the K star primary. We propose that photoexcitation by the hot star's UV continuum, followed by recombination and cascades, leads to resonant scattering and subsequent pumping of lower opacity transitions in the singlet and triplet systems of Si i. This process channels the UV continuum into select narrow emission lines. We have also identified weaker photoexcited emission of Fe ii at λ 3938.289 Å. The strengths, positions, and widths of the λ 3905 Å emission line vary with orbital phase owing to changes in the dilution of the irradiating flux and in the geometrical aspect of the irradiated hemisphere. Utilizing the inherent spatial resolution provided by the illuminated patch, and assuming that the K star is spherical with isotropic emission, yields vsin i ∼ 5.7 km s−1. Evidence of tidal distortion was deduced from the timing of the rapidly rising phase of the emission just after periastron. Increasing the diagnostic potential requires radiative transfer modelling of the formation and centre-to-limb variation of the emission.

Cuntz (1997) suggested that apparent velocity shifts in Fe II emission lines observed in Betelgeuse ( Orionis: M2 Iab) indicate that non-magnetic wave modes are relevant for the heating and dynamics of Ori's chromosphere. This claim was based on the similarity of computed stochastic velocities in 1-D short-period acoustic wave models and velocity shifts in prole ts to Fe II emission lines (Carpenter & Robinson 1997), which is now identied as coincidental. While acoustic waves may indeed be important for the heating and dynamics of Ori's chromosphere, the interpretation of the Fe II emission line proles does not provide evidence for this possibility. The line formation of optically thick scattering lines in an extended outflow makes Fe II emission lines poorly suited as a diagnostic for small-scale structure in hydrodynamical models. Better diagnostics include electron density sensitive, low opacity lines such as C II). In the view of these ndings, we discuss directions of future research.

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., accepted for publication in A&A (April 5, 2011)

During our recent spectroscopic study of ε Aur (Chadima et al. 2011), we made an attempt to detect weak spectral lines of the secondary, hidden in a dark disk, using the spectral disentangling technique of Simon & Sturm (1994) and Hadrava (1995, 1997, 2004). We used the Dominion Astrophysical Observatory (DAO) and Ondřejov (OND) red electronic spectra, which cover more than one half of the orbital period. To our surprise, two different programs that disentangled the spectrum in Fourier space, KOREL (Hadrava 1995, 2004) and FDBINARY (Ilijić et al. 2001), both yielded apparently good, similar reconstructions of two well-defined spectra for mass ratios near unity. The results (Solution 1) are shown in Fig. 1 (left panels) and Table 1 (left column). This result is hard to accept as real given the existing knowledge about the system: ε Aur is an F-type star with an unseen companion embedded in a cool, dark disk (temperature ~ 500–600 K). A detailed search for any trace of spectral signatures of the secondary in the spectra was carried out (see Bennett et al., these proceedings). Although they found line profile variations that were correlated with orbital phase, these variations were not consistent with the presence of a secondary.

The enigmatic long period (P = 27.1 yr) eclipsing binary, ε Aurigae, recently emerged from its 2009–2011 eclipse. We have analyzed out-of-eclipse observations (Chadima et al. 2010) obtained over the past 17 years: 306 medium-resolution, high S/N, spectroscopic observations from 6300–6700 Å. Of these, 105 spectra were obtained at the Dominion Astrophysical Observatory (DAO) near Victoria, Canada, from 1994–2010, and 201 spectra were obtained at Ondřejov Observatory (OND), from 2006–2010. Analyzing these data, Chadima et al. (these proceedings) reported on a positive, but ultimately spurious, detection of a secondary spectrum. Their attempts at disentangling the binary spectra were foiled by line profile variations of the F star primary. The 6300-6700 Å spectral region contains several strong stellar lines but space limitations allow us to present only the results for Si II 6347 Å. We examine the centroids and higher moments of this prominent F star spectral line for any evidence of a secondary spectrum. Even if secondary contributions are blended with the F star lines, contamination by the secondary star should produce a centroid shift that is anti-correlated with the orbit of the F star primary.

Hyperbaric oxygen therapy appears to be a beneficial adjunctive treatment modality in the management of radionecrosis of bone and soft tissue in the head and neck. The mechanism of such wound healing enhancement appears to be related to oxygen stimulation of fibroblastic activity and neovasculation. In this pilot study, involving 13 cases of refractory mandibular radionecrosis treated with hyperbaric oxygen, complete healing of soft tissue disease with covering of exposed bone has been noted in seven cases 11 to 27 months posttreatment; transient healing was seen in three cases; moderate to marked improvement in soft tissue disease has been noted in three cases. Pain relief was marked in six cases, moderate in four cases, and slight in one case of the 11 patients with significant pretreatment pain. Radiographic improvement was slight to moderate in ten cases. Four of the five patients with pathologic fractures developed a firm fibrous union of the mandibular segments during or shortly after treatment. Three additional cases of head and neck radionecrosis of other sites have noted significant improvement in their lesions during treatment. Three other patients with radionecrosis of the foot, hip, and vagina have also been treated with good results only in the vaginal case. None of the 19 patients treated with hyperbaric oxygen developed persistent or significant complications.

An identification of CaCl in the IUE spectra of N-type carbon stars is proposed. This is based primarily on the coincidence of several strong and previously unidentified stellar features with the strongest band heads of the D-X system of CaCl. It is possible that these lines carry information about the upper photosphere and perhaps even the temperature minimum.