SIMBAD references

We performed a period search of the 109 published radial velocities of 9 Sge (HD 188001) obtained since 1921 and found a dominant period of 78.74 day plus its first harmonic. We confirm earlier suggestions that the O8 If star 9 Sge is an SB1 binary of small amplitude (K ∼ 11 km s ^-1). Our improved set of orbital elements indicate the companion may be a small star whose mass is probbly in the range 1.2 - 1.9 solar mass. This permits a non-degenerat dwarf companion as early as A-type, which would not be detectable in contrast with the bright primary star.