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arXiv · 0808.2630

Identification of the TW Hya Association member 2M1235$-$39: a tertiary component of the HR 4796 system

Joel H. Kastner·B. Zuckerman·M. Bessell
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Abstract

The association of the late-type star 2MASS J12354893-3950245 (2M1235-39) with a bright X-ray source detected serendipitously by ROSAT and XMM-Newton, combined with its proximity to the well-studied (A+M binary) system HR 4796, suggests this star is a member of the TW Hya Association (TWA). To test this hypothesis, we used optical spectroscopy to establish the Li and H-alpha line strengths and spectral type of 2M1235-39, and determined its proper motion via optical imaging. The Li absorption and H-alpha emission line strengths of 2M1235-39, its near-IR and X-ray fluxes, and its proper motion all indicate that 2M1235-39 is a TWA member. Most likely this star is a wide (13,500 AU) separation, low-mass (M4.5), tertiary component of the HR 4796 system.

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Joel H. Kastner, B. Zuckerman, M. Bessell. 2008-08-19. Identification of the TW Hya Association member 2M1235$-$39: a tertiary component of the HR 4796 system. https://doi.org/10.1051/0004-6361%3A200810580

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