Studies of multiple stellar systems - IV. The triple-lined spectroscopic system Gliese 644

Abstract

We present a radial-velocity study of the triple-lined system Gliese 644 and derive spectroscopic elements for the inner and outer orbits with periods of 2.9655 and 627 days. We also utilize old visual data, as well as modern speckle and adaptive optics observations, to derive a new astrometric solution for the outer orbit. These two orbits together allow us to derive masses for each of the three components in the system: M_A = 0.410 +/- 0.028 (6.9%), M_Ba = 0.336 +/- 0.016 (4.7%), and $M_Bb = 0.304 +/- 0.014 (4.7%) M_solar. We suggest that the relative inclination of the two orbits is very small. Our individual masses and spectroscopic light ratios for the three M stars in the Gliese 644 system provide three points for the mass-luminosity relation near the bottom of the Main Sequence, where the relation is poorly determined. These three points agree well with theoretical models for solar metallicity and an age of 5 Gyr. Our radial velocities for Gliese 643 and vB 8, two common-proper-motion companions of Gliese 644, support the interpretation that all five M stars are moving together in a physically bound group. We discuss possible scenarios for the formation and evolution of this configuration, such as the formation of all five stars in a sequence of fragmentation events leading directly to the hierarchical configuration now observed, versus formation in a small N cluster with subsequent dynamical evolution into the present hierarchical configuration.

17 pages, 9 figures, Accepted for publication in MNRAS

References in corpus (3)

• Predicting the Properties of Binary Stellar Systems: The Evolution of Accreting Protobinary Systems
• Interferometric Astrometry of the Low-mass Binary Gl 791.2 (= HU Del) Using Hubble Space Telescope Fine Guidance Sensor 3: Parallax and Component Masses
• Studies of multiple stellar systems - III. Modulation of orbital elements in the triple-lined system HD 109648

Cited by in corpus (17)

• The 0.4-Mo Eclipsing Binary CU Cancri: Absolute Dimensions, Comparison with Evolutionary Models and Possible Evidence for a Circumstellar Dust Disk
• New Observational Constraints on the Winds of M Dwarf Stars
• The M-dwarfs in Multiples (MinMs) survey - I. Stellar multiplicity among low-mass stars within 15 pc
• On the properties of young multiple stars
• Southern wide very low-mass stars and brown dwarfs in resolved binary and multiple systems
• Common Proper Motion Companions to Nearby Stars: Ages and Evolution
• IR Detection of Low-Mass Secondaries in Spectroscopic Binaries
• The relative emission from chromospheres and coronae: dependence on spectral type and age
• The CARMENES search for exoplanets around M dwarfs: Nine new double-line spectroscopic binary stars
• A New Method for Classifying Flares of UV Ceti Type Stars: Differences Between Slow and Fast Flares
• Saturation Levels for White-light Flares of Flare Stars: Variation of Minimum Flare Duration for Saturation
• Are the orbital poles of binary stars in the solar neighbourhood anisotropically distributed?
• Cross-correlation in four dimensions: Application to the quadruple-lined spectroscopic system HD 110555
• The statistical analyses of flares detected in B band photometry of UV Ceti type stars
• Rotation Modulations and Distributions of the Flare Occurrence Rates on the Surface of Five UV Ceti Type Stars
• Spitzer 24-micron Time-Series Observations of the Eclipsing M-dwarf Binary GU Bootis
• Correlating Intrinsic Stellar Parameters with Mg II Self-Reversal Depths