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A Surprising Dynamical Mass for V773 Tau B

Boden, Andrew F. and Torres, Guillermo and Duchêne, Gaspard and Konopacky, Quinn and Ghez, A. M. and Torres, Rosa M. and Loinard, Laurent (2012) A Surprising Dynamical Mass for V773 Tau B. Astrophysical Journal, 747 (1). Art. No. 17. ISSN 0004-637X.

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We report on new high-resolution imaging and spectroscopy on the multiple T Tauri star system V773 Tau over the 2003-2009 period. With these data we derive relative astrometry, photometry between the A and B components, and radial velocity (RV) of the A-subsystem components. Combining these new data with previously published astrometry and RVs, we update the relative A-B orbit model. This updated orbit model, the known system distance, and A-subsystem parameters yield a dynamical mass for the B component for the first time. Remarkably, the derived B dynamical mass is in the range 1.7-3.0 M_☉. This is much higher than previous estimates and suggests that like A, B is also a multiple stellar system. Among these data, spatially resolved spectroscopy provides new insight into the nature of the B component. Similar to A, these near-IR spectra indicate that the dominant source in B is of mid-K spectral type. If B is in fact a multiple star system as suggested by the dynamical mass estimate, the simplest assumption is that B is composed of similar ~1.2 M_☉ pre-main-sequence stars in a close (<1 AU) binary system. This inference is supported by line-shape changes in near-IR spectroscopy of B, tentatively interpreted as changing RV among components in V773 Tau B. Relative photometry indicates that B is highly variable in the near-IR. The most likely explanation for this variability is circum-B material resulting in variable line-of-sight extinction. The distribution of this material must be significantly affected by both the putative B multiplicity and the A-B orbit.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Torres, Guillermo0000-0002-5286-0251
Konopacky, Quinn0000-0002-9936-6285
Ghez, A. M.0000-0003-3230-5055
Loinard, Laurent0000-0002-5635-3345
Additional Information:© 2012 American Astronomical Society. Received 2011 March 18; accepted 2011 November 29; published 2012 February 10. Some of the data presented here were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, the University of Hawaii, and NASA. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. We gratefully acknowledge personnel from the W.M. Keck Observatory in supporting observations of V773 Tau. The authors recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. The authors gratefully acknowledge research support provided by the National Science Foundation, the California Institute of Technology, Harvard University, the University of California, DGAPA, UNAM, and CONACyT, Mexico. In particular: A.F.B. acknowledges support from NSF grant AST-0908822, G.T. acknowledges support from NSF grant AST-1007992, R.M.T. acknowledges support by the Deutsche Forschungsgemeinschaft (DFG) through the Emmy Noether Research grant VL 61/3-1. L.L. acknowledges the financial support of the Guggenheim Foundation and the von Humboldt Stiftung. Portions of this work were performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Harvard UniversityUNSPECIFIED
University of CaliforniaUNSPECIFIED
Dirección General Asuntos del Personal Académico (DGAPA)UNSPECIFIED
Universidad Nacional Autónoma de México (UNAM)UNSPECIFIED
Consejo Nacional de Ciencia y Tecnología (CONACYT)UNSPECIFIED
Deutsche Forschungsgemeinschaft (DFG)VL 61/3-1
John Simon Guggenheim FoundationUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Department of Energy (DOE)DE-AC52-07NA27344
Subject Keywords: stars: fundamental parameters; stars: individual (V773 Tau); stars: pre-main sequence
Issue or Number:1
Record Number:CaltechAUTHORS:20120326-084936681
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Official Citation: A Surprising Dynamical Mass for V773 Tau B Andrew F. Boden et al. 2012 ApJ 747 17
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29837
Deposited By: Ruth Sustaita
Deposited On:26 Mar 2012 16:20
Last Modified:14 Oct 2019 22:14

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