Orbit of the Speckle Interferometric Binary System HIP 10944

Massive stars that form the Gould Belt OB associations are known to have higher multiplicity than solar-type stars. Due to their luminosity and close vicinity, they are optimal targets for speckle interferometry. Among the members of the Cas–Tau OB association, observed with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences (BTA SAO RAS), a binary system, HI P10944 (B9VpSi, $$G=5\overset{\textrm{m}}{.}53$$ ), was discovered for the first time. We present the results of speckle interferometry monitoring of the star from 2007 to 2025, covering almost the entire orbital period ( $$P_{\textrm{orb}}=20.90$$ yrs). Based on the measured positional parameters, an orbit was constructed and the sum of the masses of the system’s components was determined ( $$M_{*}=4.26\pm 0.06M_{\odot}$$ ).