The visual orbit of HD 98800

Abstract

A family of possible visual orbits is computed for HD 98800AB, a young quadruple system of red dwarfs with a dusty disk. Published visual measurements, the radial-velocity difference, and an estimate of the sum of the component masses are used. Orbits with eccentricities from 0.3 to 0.6 and periods from 300 to 430 years result in dynamical parallaxes which are in agreement with measurements from Hipparcos, within its accuracy. Thus, the orbit HD 98800 is not distinguished by an extremely high eccentricity as was thought previously, but has quite typical parameters. The orbital inclination is close to 90 deg, and the object is observed through the surrounding dusty disk. The components probably interact with the disk.