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arXiv · 1012.2642

Revealing the Chamaeleon: First detection of a low-mass stellar halo around the young open cluster Eta Chamaeleontis

Simon J. Murphy·Warrick A. Lawson·Michael S. Bessell
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Abstract

We have identified several lithium-rich low-mass (0.08<M<0.3 Msun). stars within 5.5 deg of the young open cluster Eta Chamaeleontis, nearly four times the radius of previous search efforts. We propose 4 new probable cluster members and 3 possible members requiring further investigation. Candidates were selected on the basis of DENIS and 2MASS photometry, NOMAD astrometry and extensive follow-up spectroscopy. Several of these stars show substantial variation in their H-alpha emission line strengths on timescales of days to months, with at least one event attributable to accretion from a circumstellar disk. These findings are consistent with a dynamical origin for the current configuration of the cluster, without the need to invoke an abnormally top-heavy Initial Mass Function, as proposed by some authors.

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Simon J. Murphy, Warrick A. Lawson, Michael S. Bessell. 2010-12-13. Revealing the Chamaeleon: First detection of a low-mass stellar halo around the young open cluster Eta Chamaeleontis. https://arxiv.org/abs/1012.2642

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