ID | Name |
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Age (isochrones) | Age (Ca II) | [Fe/H] |
(kms-1) | (kms-1) | (kms-1) | (Gyr) | (Gyr) | |||
HD 10780 | -14.8 | -11.3 | 1.6 | - | -0.02 | ||
HD 32147 | 10.7 | -51.8 | -6.3 | - | 0.28 | ||
HD 99491 | -49.8 | -4.1 | -8.7 | 12.6-15.8 | 0.22 | ||
HD 104304 | 31.6 | -10.2 | -9.2 | ![]() |
0.15 | ||
HD 121370 | 19.2 | -12.0 | 4.6 | 2.5-3.2 | 0.24 | ||
HD 145675 | 14 Her | 35.6 | -2.0 | -2.9 | 10-13.0 | 0.47 | |
HD 182572 | -106.7 | -25.2 | -13.5 | 7.9-10.0 | 0.34 | ||
HD 196755 | -48.1 | 29. | -11.7 | 2.5-3.2 | 0.02 | ||
HD 9826 | ![]() |
4.3 | -34.1 | 0.6 | 2.7 | 0.12 | |
HD 75732 | ![]() |
-27.3 | -13.2 | -0.9 | 5 | 0.45 | |
HD 75289 | 31.1 | -12.4 | -14.5 | 2.1 | 0.28 | ||
HD 95128 | 47 UMa | -14.7 | 2.6 | 8.8 | 6.3 | 7 | 0.01 |
HD 117176 | 70 Vir | 23.2 | -46.9 | 3.4 | 8 | 9 | -0.03 |
HD 120136 | ![]() |
-23.5 | -13.8 | 0.3 | 1 | 0.32 | |
HD 143761 | ![]() |
64.1 | -30.7 | 28.5 | 12.3 | -0.29 | |
HD 186408 | 16 Cyg A | 27.6 | -23.6 | 7.2 | 9.0 | 0.11 | |
HD 186427 | 16 Cyg B | 27.1 | -24.7 | 5.4 | 9.0 | 7 | 0.06 |
HD 187123 | 11.6 | -10.6 | -36.4 | 5.5 | 0.16 | ||
HD 217014 | 51 Peg | -5.6 | -24.2 | 22.3 | 6.0 | 10 | 0.21 |
HD 210277 | 12.4 | -46.8 | 3.0 | 8.5 | 0.24 |
Spatial velocity data were calculated using the Hipparcos parallaxes and proper motions. Radial velocities were taken from Barbier-Brossat et al. (1994). For our stars the uncertainties in the parallaxes are small, less than 3% of the parallax, Table 1. Data were also obtained for the stars from the Gonzalez (1999) compilation. The velocities are presented in Table 8. Note that we here quote the velocities relative to the local standard of rest (LSR) and Gonzalez (1999) quoted velocities relative to the sun.
From Table 8 we see that all the stars have
W-velocities well below the
of the general population of
stars with similar B-V. Figure 5 in Dehnen &
Binney (1998) illustrates how
varies with B-V.
Also, most of the stars in Table
8 have both V and U-velocities well below 1
for the general population. We have
quantified this by calculating the probabilities that any one of our
stars belongs to either the thin or the thick disk by using a model
where 94% of the solar neighbourhood stars belong to a thin disk
with
,
,
and
kms-1 and the
remaining 6% to the thick disk with
,
,
and
kms-1. Only one of our stars, HD 182572, has a
probability that it belongs to the thick disk larger than that
it should belong to the thin. We estimate that, given the galactic
model, this star has 75% chance of belonging to the thick disk.
Thus, we conclude that our SMR and
planet-bearing stars samples the thin disk.
Fuhrmann (1998) found that
stars with thick disk kinematics were enhanced in [Mg/Fe] as compared
to thin disk stars at the same metallicity. We
have not measured Mg lines in our spectra. We did, however, measure Si, and our
abundance result for HD 182572 gives [Si/Fe]
.
Compared with the general trend of [Si/Fe] for metal-rich
stars in Feltzing & Gustafsson (1998), this is above the mean;
however, their data exhibit a large scatter.
We have also determined Ca abundances for this
star, however, only one line was available. This line seems to give
fairly low Ca abundances in all of the stars with more than
two lines observed and may thus be underestimating the true Ca abundance
in this star. Note that it is not inconsistent that we also
find thin disk stars with the same Si abundance as, if HD 182572 is a
thick disk star, then it might be showing us the abundance trend after
the decline in [X/Fe], where X is either O or an
-element,
sets in due to increasing relative contribution
of SNIa.
Copyright ESO 2001