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The simulated appearance from Earth of the VV Cep binary system at phase 0.95, approximately 12 months before mid-eclipse at phase 1.0 (anti-clockwise orbits), near the anticipated time of first contact of the gas disc circulating anticlockwise around the hot blue star (for visibility the blue star diameter is significantly exaggerated). This is a snapshot from a video made by the author using the Nebraska Astronomy Applet Project’s Binary Star Simulator, astro.unl.edu/naap/ebs/animations/ebs.html. Orbital parameters are taken from Hopkins et al. (2015).

Observing the 2017–’19 primary eclipse of VV Cephei with a low-resolution spectroscope

The 2017–’19 primary eclipse of the red supergiant star VV Cephei has been monitored with low-resolution spectroscopy, by following changes in the hydrogen Balmer emission lines in the spectrum. A number of characteristics of the binary system are derived from the high cadence of observations, including a surprising estimate of 7,425 days for the orbital period since the midpoint of the last eclipse. The appearance of the spectrum near mid-eclipse has also provided a means to estimate interstellar reddening.

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