SCYON Abstract

Received on February 5 2003

The superwind mass-loss rate of the metal-poor carbon star LI-LMC 1813 in the LMC cluster KMHK 1603

Authors	Jacco Th. van Loon ¹, Jonathan R. Marshall ¹, Mikako Matsuura ², Albert A. Zijlstra ²
Affiliation	¹ Astrophysics Group, School of Chemistry & Physics, Keele University, Staffordshire ST5 5BG, United Kingdom ² UMIST, Department of Physics, P.O. Box 88, Manchester M60 1QD, United Kingdom
Accepted by	Monthly Notices of the Royal Astronomical Society
Contact	jacco@astro.keele.ac.uk
URL
Links

Abstract

LI-LMC 1813 is a dust-enshrouded Asymptotic Giant Branch (AGB) star, located in the small open cluster KMHK 1603 near the rim of the Large Magellanic Cloud (LMC). Optical and infrared photometry between 0.5 and 60 µ is obtained to constrain the spectral energy distribution of LI-LMC 1813. Near-infrared spectra unambiguously show it to be a carbon star. Modelling with the radiation transfer code Dusty yields accurate values for the bolometric luminosity, L = 1.5 x 10⁴ L_o, and mass-loss rate, dM/dt = 3.7 (± 1.2) x 10^-5 M_o yr^-1. On the basis of colour-magnitude diagrams, the age of the cluster KMHK 1603 is estimated to be t = 0.9 - 1.0 Gyr, which implies a Zero-Age Main Sequence mass for LI-LMC 1813 of M_ZAMS = 2.2 ± 0.1 M_o. This makes LI-LMC 1813 arguably the object with the most accurately and reliably determined (circum)stellar parameters amongst all carbon stars in the superwind phase.