Open AccessStudies of multiple stellar systems – III. Modulation of orbital elements in the triple‐lined system HD 109648
Author(s) -
Jha Saurabh,
Torres Guillermo,
Stefanik Robert P.,
Latham David W.,
Mazeh Tsevi
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03592.x
Subject(s) - physics , eccentricity (behavior) , orbital elements , triple system , orbit (dynamics) , astrophysics , radial velocity , modulation (music) , orientation (vector space) , orbital inclination , binary number , stars , amplitude , orbital eccentricity , binary star , circular orbit , optics , geometry , mathematics , acoustics , arithmetic , engineering , political science , law , aerospace engineering
The triple‐lined spectroscopic triple system HD 109648 has one of the shortest periods known for the outer orbit in a late‐type triple, 120.5 d, and the ratio between the periods of the outer and the inner orbits is small, 22:1. With such extreme values, this system should show orbital element variations over a time‐scale of about a decade. We have monitored the radial velocities of HD 109648 with the CfA Digital Speedometers for 8 yr, and have found evidence for modulation of some orbital elements. While we see no definite evidence for modulation of the inner binary eccentricity, we clearly observe variations in the inner and the outer longitudes of periastron, and in the radial velocity amplitudes of the three components. The observational results, combined with numerical simulations, allow us to put constraints on the orientation of the orbits.