The Triple System HR 7272

A combined spectroscopic-interferometric orbit is computed for the primary component of the visual binary star HR 7272 = ADS 12101. The orbital period is 3.55 years; semimajor axis 0.074 arcsec. Radial velocities of both components were determined by correlation techniques; their semi-amplitudes are 6.6 and 8.4 km/s. Because those amplitudes are so modest, the correlation dips are never well resolved, and the mass ratio and orbital parallax remain poorly determined. Adopting normal masses for the components, we obtain the dynamical parallax; the Hipparcos parallax for this star seems to have a large error, probably because the orbital motion was not taken into account. The visual component B belongs to this system and has a constant radial velocity.