Keck Diffraction-Limited Imaging of the Young Quadruple Star System HD 98800.pdfVIP

Keck Diffraction-Limited Imaging of the Young Quadruple Star System HD 988001 L. Prato2 and A. M. Ghez3 Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1562 0 R. K. Pi˜na, C. M. Telesco, and R. S. Fisher 0 0 Department of Astronomy, University of Florida, Gainesville, FL 32611 2 v P. Wizinowich, O. Lai, D. S. Acton, and P. Stomski o N W. M. Keck Observatory, 65-1120 Mamalahoa Hwy, Kamuela, HI 96743 0 1 ABSTRACT 2 v This paper presents diffraction-limited 1−18µm images of the young quadruple star 5 3 system HD 98800 obtained with the W. M. Keck 10-m telescopes using speckle and 1 adaptive optics imaging at near-infrared wavelengths and direct imaging at mid-infrared 1 1 wavelengths. The two components of the visual binary, A and B, both themselves 0 spectroscopic binaries, were separable at all wavelengths, allowing us to determine their 0 / stellar and circumstellar properties. Combining these observations with spectroscopic h 7 p data from the literature, we derive an age of ∼10 years, masses of 0.93 and 0.64 M⊙ and o- an inclination angle of 58◦ for the spectroscopic components of HD 98800 B, and an age r of ∼107 years and a mass of 1.1 M⊙ for HD 98800 Aa. Our data confirm that the large t s mid-infrared excess is entirely associated with HD 98800 B. This excess exhibits a black a : body temperature of 150 K and a strong 10µm s