A Surprising Dynamical Mass for V773 Tau B
Abstract
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.
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.Attached Files
Published - Boden2012p17552Astrophys_J.pdf
Files
Name | Size | Download all |
---|---|---|
md5:56d0dabdb3ea83acd9f7be859f4932ec
|
562.5 kB | Preview Download |
Additional details
- Eprint ID
- 29837
- Resolver ID
- CaltechAUTHORS:20120326-084936681
- W. M. Keck Foundation
- NSF
- Caltech
- Harvard University
- University of California
- Dirección General Asuntos del Personal Académico (DGAPA)
- Universidad Nacional Autónoma de México (UNAM)
- Consejo Nacional de Ciencia y Tecnología (CONACYT)
- AST-0908822
- NSF
- AST-1007992
- NSF
- VL 61/3-1
- Deutsche Forschungsgemeinschaft (DFG)
- John Simon Guggenheim Foundation
- Alfred P. Sloan Foundation
- DE-AC52-07NA27344
- Department of Energy (DOE)
- Created
-
2012-03-26Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field