Abstract: Manfred Schwarz (Wiener Neustadt, Austria), a colleague of Dr. Ernst Pollmann, wries: Thanks to the previous campaigns and the great efforts of amateur astronomers, VV Cephei is one of the best observed stars in the northern hemisphere. The large amount of data allows new insights into the system that are not covered by professional astronomers previously. Another high-cadence spectroscopic observation would now be necessary as the B component approaches the periastron. Ernst Pollmann predicts a disturbance of the disc precession 43-day-period by mass exchange from the M supergiant to the B component during the coming orbital phase started in 2025. It would be interesting to see whether this long-term process will change the 43-day precession period of the B star’s rotational axis. All of this can only be determined through long-term spectroscopic observation of this system. Thank you for your support.
Justification: “VV Cephei is a binary star consisting of an M-type supergiant star and a B-type companion on an orbit of 20.36 years. A lot of amateur and professional astronomers as well did contribute particularly during the eclipse 2017-2019 with high professional spectra of the Hα region. Ernst Pollmann collected all the spectra and performed a new wavelength calibration with typical metal lines of the M-star (according to K. O. Wright) to archive a correct and common base for evaluation of the Hα profile. That procedure leads to discover a new unknown periodic behaviour of R/V and EW(R), EW(V) of 43 days. Together with Philip Bennett (University of Halifax), they found a plausible explanation for that periodicity. The 43 day-period is produced by the precession of the rotational axis of the B star. This variability was also measured during the eclipses, where the disk was completely behind the M-star. Therefore, Philip Bennett proposed a model of two Hα emission lobes developing primary in the accretion disk.” For more information on this campaign, please see the campaign paper here: https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://forum.astronomie.de/attachments/vv-cep-2025-pdf.432428/&ved=2ahUKEwib-rP9rdCMAxVawvACHWgoC-YQFnoECCAQAQ&usg=AOvVaw303lytPf4Q49Id1K_ZYKWP