A Photometric Analysis of Seventeen Binary Stars Using Speckle Imaging

Abstract

Magnitude differences obtained from speckle imaging are used in combination with other data in the literature to place the components of binary star systems on the H-R diagram. Isochrones are compared with the positions obtained, and a best-fit isochrone is determined for each system, yielding both masses of the components as well as an age range consistent with the system parameters. Seventeen systems are studied, 12 of which were observed with the 0.6 m Lowell-Tololo Telescope at Cerro Tololo Inter-American Observatory and six of which were observed with the WIYN 3.5 m Telescope (The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories) at Kitt Peak. One system was observed from both sites. In comparing photometric masses to mass information from orbit determinations, we find that the photometric masses agree very well with the dynamical masses, and are generally more precise. For three systems, no dynamical masses exist at present, and therefore the photometrically determined values are the first mass estimates derived for these components.

Inner and Outer Orbits in 13 Resolved Hierarchical Stellar Systems

“…Table 5 gives the combined and individual magnitudes of ADS 15988 in the V and K bands based on the available data. The magnitude difference between A and B has been measured by Davidson et al (2009) (∆V = 1.50 ± 0.05 mag, ∆R = 1.35 ± 0.07 mag), by Fabricius & Makarov (2000) (∆V = 1.51 mag, ∆B = 1.78 mag), and by Hipparcos (∆Hp = 1.539 mag). It is clear that B is slightly redder than A.…”

MOST SUB-ARCSECOND COMPANIONS OFKEPLEREXOPLANET CANDIDATE HOST STARS ARE GRAVITATIONALLY BOUND

“…Finding a companion to a KOI star typically corresponds to the identification of a binary host star with one or more exoplanets. Our continued observations of Kepler and other exoplanet host stars will provide high-precision magnitudes and colors of stellar components, eventually allowing us to use isochrone fitting to place the stars on the H-R diagram, as discussed in Davidson et al (2009). Such analyses can yield mass information of the components, and if one component is evolved, to estimate the age of such systems.…”

The WIYN Speckle Survey: Toward the Thin and Thick Disk Binary Populations

“…Our recent work in Davidson et al [8] analyzed seventeen systems in this way and derived -photometric‖ masses for the components based on isochrones fitting. In cases where dynamical masses were known, the speckle photometric results were consistent with these mass values, and generally of higher precision.…”

“…To answer this question, we need to show the same kind of result as in Figure 4 for many speckle binaries. We are in the process of completing this type of study for ~20 more systems beyond those already analyzed in Davidson et al [8], all very close to the Sun, and all with extremely well-known visual/speckle orbits. Most have near-solar metallicity.…”