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We confirmed the binary nature of the Be star 7~Vul, derived a~more accuratespectroscopic orbit with an orbital period of (69.4212+/-0.0034) d, andimproved the knowledge of the basic physical elements of the system. Analyzingavailable photometry and the strength of the \ha emission, we also document thelong-term spectral variations of the Be primary. In addition, we confirmedrapid light changes with a~period of 0.5592 d, which is comparable to theexpected rotational period of the Be primary, but note that its amplitude andpossibly its period vary with time. We were able to disentangle only the He I6678 A line of the secondary, which could support our tentative conclusion thatthe secondary appears to be a hot subdwarf. A search for this object inhigh-dispersion far-UV spectra could provide confirmation. Probable masses ofthe binary components are ($6\pm1$)~Mnom \ and ($0.6\pm0.1$)~Mnom. If thepresence of a hot subdwarf is firmly confirmed, 7 Vul might be identified as arare object with a B4-B5 primary; all Be + hot subdwarf systems found so farcontain B0-B3 primaries.

A new study of the spectroscopic binary 7 Vul with a Be star primary