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Paper: |
Small Planets Do Not Require a Metal-Rich Environment |
Volume: |
472, New Quests in Stellar Astrophysics III: A Panchromatic View of Solar-like Stars, With and Without Planets |
Page: |
91 |
Authors: |
Latham, D. W.; Buchhave, L. A.; Kepler Team |
Abstract: |
The abundance of heavy elements in the photospheres of planet-hosting
stars similar to the Sun may provide a record of the chemical
composition of their initial protoplanetary discs. Several studies
have shown that metal-rich stars are much more likely to harbor gas
giant planets, thereby supporting the core accretion scenario for
giant planet formation. The large sample of transiting planets smaller
than Neptune identified by the Kepler mission provides a first
opportunity to probe the metallicities of a statistically significant
number of stars with small planets. We have derived spectroscopic
metallicities for 152 stars hosting 226 planet candidates discovered by
Kepler and find that, in contrast to the preference for gas
giants to be found around metal-rich stars, the detection of planets
smaller than Neptune does not depend as strongly on the metallicity of
the host star. Planets smaller than 4 Earth radii are found around
host stars with a wide range of metallicities. |
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