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Session 43 - Binary Stars.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center
We present recent results from Hubble Space Telescope FOS observations of the nearby red dwarf binary Ross 614 A,B. Using the high spatial resolution of HST resulting from the 1993 Servicing Mission, together with the small apertures of the FOS, we have obtained a separate, unblended spectrum for each component. The pair is currently at a two thirds arc-second separation. The FOS was peaked-up on Ross 614 A for a spectrum of the primary, then offset by the orbital ephemeris for B and a second peak-up performed before the spectrum of B was taken. The spectral wavelengths range from .63 to .85nm. Ross 614 B is of particular interest because it has a dynamically well-determined mass of 0.083 \pm 0.023 M_\sun (Coppenbarger et al., 1994, AJ, 107,1551), very near the nominal red dwarf/brown dwarf border of 0.08 M_\sun.
With a spectral type determined from the unblended FOS observations, Ross 614 B becomes the star with smallest known mass which also has a well-determined spectral type. Spectral classification of this star will provide an important spectrum-mass reference point for red dwarfs, near and beyond the end of the main sequence.
Support for this work was provided by NASA through grant number 06048 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS5-26555.
Program listing for Tuesday