Bibcode
González-Hernández, J. I.; Israelian, G.; Santos, N. C.; Sousa, S.; Delgado-Mena, E.; Neves, V.; Udry, S.
Bibliographical reference
The Astrophysical Journal, Volume 720, Issue 2, pp. 1592-1602 (2010).
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9
2010
Journal
Citations
114
Refereed citations
92
Description
We present a fully differential chemical abundance analysis using very
high resolution (λ/δλ >~ 85, 000) and very high
signal-to-noise (S/N ~800 on average) HARPS and UVES spectra of 7 solar
twins and 95 solar analogs, of which 24 are planet hosts and 71 are
stars without detected planets. The whole sample of solar analogs
provides very accurate Galactic chemical evolution trends in the
metallicity range -0.3 < [Fe/H] < 0.5. Solar twins with and
without planets show similar mean abundance ratios. We have also
analyzed a sub-sample of 28 solar analogs, 14 planet hosts, and 14 stars
without known planets, with spectra at S/N ~850 on average, in the
metallicity range 0.14 < [Fe/H] < 0.36, and find the same
abundance pattern for both samples of stars with and without planets.
This result does not depend on either the planet mass, from 7 Earth
masses to 17.4 Jupiter masses, or the orbital period of the planets,
from 3 to 4300 days. In addition, we have derived the slope of the
abundance ratios as a function of the condensation temperature for each
star and again find similar distributions of the slopes for both stars
with and without planets. In particular, the peaks of these two
distributions are placed at a similar value but with the opposite sign
to that expected from a possible signature of terrestrial planets. In
particular, two of the planetary systems in this sample, each of them
containing a super-Earth-like planet, show slope values very close to
these peaks, which may suggest that these abundance patterns are not
related to the presence of terrestrial planets.
Related projects
Observational Tests of the Processes of Nucleosynthesis in the Universe
Several spectroscopic analyses of stars with planets have recently been carried out. One of the most remarkable results is that planet-harbouring stars are on average more metal-rich than solar-type disc stars. Two main explanations have been suggested to link this metallicity excess with the presence of planets. The first of these, the “self
Garik
Israelian