7 Vulpeculae

 
 
7 Vulpeculae is a binary star system approximately 940 light years away in the northern constellation of Vulpecula. It is a challenge to view with the naked eye, having an apparent visual magnitude of 6.34. The system is moving closer to the Earth with a heliocentric radial velocity of −38 km/s.
This is a single-lined spectroscopic binary star system with an orbital period of 69.3 days and an eccentricity of 0.16. The visible component is a Be star with a stellar classification of B4–5 III–IVe that appears to be nearing the end of its main sequence lifetime. It shows a rapid rotation rate with a projected rotational velocity of 300 km/s, which is just below the estimated critical velocity of 367 km/s.
There is a small variability in the magnitude of this star that occurs over 0.559 days this is likely the rotation period of the primary star.
The nature of the companion is unknown, but based upon its mass it may be a K- or M-type star. However, it could be a white dwarf that has previously undergone a mass transfer event with the now visible component. Because of the lack of X-ray emission from the system, a third possibility is that the companion is a naked He star that has been stripped of its hydrogen envelope.