PI: Kevin Gullikson, University of Texas, firstname.lastname@example.org
Address: Astronomy Department, 2515 Speedway, Stop C1400, Austin, TX 78712, United States
CoI: Adam Kraus, University of Texas
Title: Searching for Disk-Born Companions to A stars
Abstract: The discovery of planets around stars such as HR 8799 and (beta) Pictoris has made A-type stars are attractive targets for direct-imaging planet searches. Close stellar companions to these stars can affect the formation and orbital evolution of any planets, and so a multiplicity survey of nearby intermediate mass stars is needed both to weed out binary systems from future planet searches and to determine the binary system properties. We propose to observe high resolution, high signal- to-noise ratio spectra of several southern intermediate-mass stars, and to observe follow-up spectra of candidates uncovered in previous semesters. We will search for companions by cross- correlating the spectra we observe against model spectra for F- to M-type secondary stars. The cross-correlation method is sensitive to mass-ratios q\equiv M_s/M_p \gtrsim 0.06-0.15 at all orbital separations less then a few tens of AU. We will use the binary population we reveal in our survey to measure the mass-ratio distribution for intermediate mass stars, which can help distinguish between companions formed through disk fragmentation and molecular core fragmentation.
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