Infrared Spectroscopy of Symbiotic Stars. II. Orbits for Five S-Type Systems with Two-Year Periods

Francis C. Fekel, Kenneth H. Hinkle, Richard R. Joyce, Michael F. Skrutskie
2000 Astronomical Journal  
Infrared radial velocities have been used to determine orbital elements for the cool giants of Ðve wellknown symbiotic systems, Z And, AG Dra, V443 Her, AX Per, and FG Ser, all of which have orbital periods near the two-year mean period for S-type symbiotics. The new orbits are in general agreement with previous orbits derived from optical velocities. From the combined optical and infrared velocities, improved orbital elements for the Ðve systems have been determined. Each of the orbital
more » ... the orbital periods has been determined solely from the radial-velocity data. The orbits are circular and have quite small mass functions of 0.001È0.03 The infrared velocities of AG Dra do not show the large orbital velocity M _ . residuals found for its optical radial velocities.
doi:10.1086/316872 fatcat:cve7ezoh6jcvpiowyvcgygo65a