From: LARRY KLAES (ljk4_at_msn.com)
Date: Wed Dec 21 2005 - 20:15:34 PST
Paper: astro-ph/0512510
Date: Tue, 20 Dec 2005 19:22:22 GMT (328kb)
Title: Chemical Composition of the Planet-Harboring Star TrES-1
Authors: A. Sozzetti (1,2), D. Yong (3), B. W. Carney (3), J. B. Laird (4), D.
W. Latham (1), G. Torres (1) ((1) Harvard-Smithsonian Center for
Astrophysics, (2) INAF - Osservatorio Astronomico di Torino, (3) University
of North Carolina, (4) Bowling Green State University)
Comments: 52 pages, 15 figures, 5 tables, accepted for publication in the
Astronomical Journal
\\
We present a detailed chemical abundance analysis of the parent star of the
transiting extrasolar planet TrES-1. Based on high-resolution Keck/HIRES and
HET/HRS spectra, we have determined abundances relative to the Sun for 16
elements (Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Y, and Ba).
The resulting average abundance of $<[$$X$/H$]>$ $= -0.02\pm0.06$ is in good
agreement with initial estimates of solar metallicity based on iron. We compare
the elemental abundances of TrES-1 with those of the sample of stars with
planets, searching for possible chemical abundance anomalies. TrES-1 appears
not to be chemically peculiar in any measurable way. We investigate possible
signs of selective accretion of refractory elements in TrES-1 and other stars
with planets, and find no statistically significant trends of metallicity
[$X$/H] with condensation temperature $T_c$. We use published abundances and
kinematic information for the sample of planet-hosting stars (including TrES-1)
and several statistical indicators to provide an updated classification in
terms of their likelihood to belong to either the thin disk or the thick disk
of the Milky Way Galaxy. TrES-1 is found to be a very likely member of the thin
disk population. By comparing $\alpha$-element abundances of planet hosts and a
large control sample of field stars, we also find that metal-rich
([Fe/H]$\gtrsim 0.0$) stars with planets appear to be systematically
underabundant in [$\alpha$/Fe] by $\approx 0.1$ dex with respect to comparison
field stars. The reason for this signature is unclear, but systematic
differences in the analysis procedures adopted by different groups cannot be
ruled out.
\\ ( http://arXiv.org/abs/astro-ph/0512510 , 328kb)
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