7 Vulpeculae is a binary star system approximately 940[1] light years away in the northern constellation of Vulpecula.[5] It is a challenge to view with the naked eye, having an apparent visual magnitude of 6.34.[2] The system is moving closer to the Earth with a heliocentric radial velocity of −38 km/s.[4]

This is a single-lined spectroscopic binary star system with an orbital period of 69.3 days and an eccentricity of 0.16.[3] 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.[3]

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.[2]

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.[3]

References

External links

• 7 Vulpeculae on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images