AN ANCIENT EXTRASOLAR SYSTEM WITH FIVE SUB-EARTH-SIZE PLANETS

@article{Campante2015ANAE,
  title={AN ANCIENT EXTRASOLAR SYSTEM WITH FIVE SUB-EARTH-SIZE PLANETS},
  author={Tiago L. Campante and Thomas Barclay and Jonathan J. Swift and Daniel Huber and Vardan Adibekyan and William D. Cochran and Christopher J. Burke and Howard T. Isaacson and Elisa V. Quintana and Guy R. Davies and V{\'i}ctor Silva Aguirre and Darin Ragozzine and Reed L. Riddle and Christoph Baranec and Sarbani Basu and William J. Chaplin and J{\o}rgen Christensen-Dalsgaard and Travis S. Metcalfe and Timothy R. Bedding and Rasmus Handberg and Dennis Stello and John M. Brewer and Saskia Hekker and Christoffer Karoff and Rea Kolbl and Nicholas M. Law and Mia S. Lundkvist and Andrea Miglio and Jason F. Rowe and Nuno C. Santos and Christa L. Van Laerhoven and Torben Arentoft and Yvonne P. Elsworth and Debra A. Fischer and Steven D. Kawaler and Hans Kjeldsen and Mikkel N. Lund and Geoffrey W. Marcy and S{\'e}rgio G. Sousa and Alessandro Sozzetti and Timothy R. White},
  journal={The Astrophysical Journal},
  year={2015},
  volume={799},
  pages={170}
}
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References

SHOWING 1-10 OF 205 REFERENCES
CHARACTERIZING THE COOL KOIs. IV. KEPLER-32 AS A PROTOTYPE FOR THE FORMATION OF COMPACT PLANETARY SYSTEMS THROUGHOUT THE GALAXY
The Kepler space telescope has opened new vistas in exoplanet discovery space by revealing populations of Earth-sized planets that provide a new context for understanding planet formation.
A rocky composition for an Earth-sized exoplanet
TLDR
Doppler spectroscopic measurements of the mass of the Earth-sized planet Kepler-78b are reported, which is similar to Earth’s, suggesting a composition of rock and iron.
An abundance of small exoplanets around stars with a wide range of metallicities
TLDR
Spectroscopic metallicities of the host stars of 226 small exoplanet candidates discovered by NASA's Kepler mission are reported, finding that planets with radii less than four Earth radii form around host stars with a wide range of metallicities (but on average a metallicity close to that of the Sun), whereas large planets preferentially form around stars with higher metallicities.
An Earth-Sized Planet in the Habitable Zone of a Cool Star
TLDR
The detection of Kepler-186f, a 1.11 ± 0.14 Earth-radius planet that is the outermost of five planets, all roughly Earth-sized, that transit a 0.47 ±0.05 solar-radius star, implying that if Kepler- 186f has an Earth-like atmosphere and water at its surface, then some of this water is likely to be in liquid form.
An Earth-mass planet orbiting α Centauri B
TLDR
The detection of an Earth-mass planet orbiting the authors' neighbour star α Centauri B, a member of the closest stellar system to the Sun, is reported.
Kepler-36: A Pair of Planets with Neighboring Orbits and Dissimilar Densities
TLDR
Another violation of the orbit-composition pattern is reported: two planets orbiting the same star with orbital distances differing by only 10% and densities differing by a factor of 8, likely a rocky “super-Earth,” whereas the other is more akin to Neptune.
A Giant Planet Around a Metal-Poor Star of Extragalactic Origin
TLDR
The detection of a close-in giant planet around a metal-poor star belonging to a group of stars that formed in a satellite galaxy of the Milky Way, which most likely has an extragalactic origin.
Three regimes of extrasolar planet radius inferred from host star metallicities
TLDR
The metallicities (that is, the abundances of elements heavier than hydrogen and helium) of more than 400 stars hosting 600 exoplanet candidates are reported, and it is found that the exoplanets can be categorized into three populations defined by statistically distinct metallicity regions.
Kepler Planet-Detection Mission: Introduction and First Results
TLDR
The planetary findings derived from the first six weeks of observations with the Kepler mission are summarized, which include the detection of five new exoplanets, which confirm the existence of planets with densities substantially lower than those predicted for gas giant planets.
An Earth-sized planet with an Earth-like density
TLDR
The planet Kepler-78b was discovered and found to have a radius of only 1.16, and the mass of this planet is 1.86 Earth masses, which implies a composition of iron and rock similar to that of the Earth.
...
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