An Earth-sized planet with an Earth-like density

@article{Pepe2013AnEP,
  title={An Earth-sized planet with an Earth-like density},
  author={Francesco A. Pepe and Andrew Collier Cameron and David W. Latham and Emilio Molinari and St{\'e}phane Udry and Aldo Stefano Bonomo and Lars A. Buchhave and David Charbonneau and Rosario Cosentino and Courtney D. Dressing and Xavier Dumusque and Pedro Figueira and Aldo Fiorenzano and S. J. Gettel and A. Harutyunyan and Rapha{\"e}lle D. Haywood and Keith D. Horne and Mercedes L{\'o}pez-Morales and Christophe Lovis and Luca Malavolta and Michel Mayor and Giusi Micela and Fatemeh Motalebi and Valerio Nascimbeni and David F. Phillips and Giampaolo Piotto and Don Pollacco and Didier Queloz and Ken Rice and Dimitar D. Sasselov and Damien S{\'e}gransan and Alessandro Sozzetti and Andrew Szentgyorgyi and Christopher A. Watson},
  journal={Nature},
  year={2013},
  volume={503},
  pages={377-380}
}
Recent analyses of data from the NASA Kepler spacecraft have established that planets with radii within 25 per cent of the Earth’s () are commonplace throughout the Galaxy, orbiting at least 16.5 per cent of Sun-like stars. Because these studies were sensitive to the sizes of the planets but not their masses, the question remains whether these Earth-sized planets are indeed similar to the Earth in bulk composition. The smallest planets for which masses have been accurately determined are Kepler… 

A rocky composition for an Earth-sized exoplanet

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.

A rocky planet transiting a nearby low-mass star

M-dwarf stars—hydrogen-burning stars that are smaller than 60 per cent of the size of the Sun—are the most common class of star in our Galaxy and outnumber Sun-like stars by a ratio of 12:1. Recent

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

The chemical composition of stars hosting small exoplanets (with radii less than four Earth radii) appears to be more diverse than that of gas-giant hosts, which tend to be metal-rich. This implies

Extrasolar planets: An infernal Earth

Two groups have been able to exploit the closeness of planet and star to make Doppler spectroscopic measurements of the mass of Kepler-78b, and calculate the planet's mean density at 5.3 and 5.57 g cm−3, very similar to Earth's and consistent with an Earth-like composition of rock and iron.

The mass of the Mars-sized exoplanet Kepler-138 b from transit timing

The sizes and masses of three planets orbiting Kepler-138, a star much fainter and cooler than the Sun, are reported, determining that the mass of the Mars-sized inner planet, Kepler- 138 b, is Earth masses and its density is grams per cubic centimetre.

Occurrence and core-envelope structure of 1–4× Earth-size planets around Sun-like stars

The Kepler mission finds the smallest planets to be most common, as 26% of Sun-like stars have small, 1–2 R⊕ planets with orbital periods under 100 d, and 11% have 1– 2 Rⵕ planets that receive 1–4× the incident stellar flux that warms the authors' Earth.

MASSES, RADII, AND ORBITS OF SMALL KEPLER PLANETS: THE TRANSITION FROM GASEOUS TO ROCKY PLANETS

We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise

REVISED MASSES AND DENSITIES OF THE PLANETS AROUND KEPLER-10

Determining which small exoplanets have stony-iron compositions is necessary for quantifying the occurrence of such planets and for understanding the physics of planet formation. Kepler-10 hosts the

A 1.9 Earth radius rocky planet and the discovery of a non-transiting planet in the Kepler-20 system

Kepler-20 is a solar-type star (V = 12.5) hosting a compact system of five transiting planets, all packed within the orbital distance of Mercury in our own Solar System. A transition from rocky to

An Earth-sized exoplanet with a Mercury-like composition

Earth, Venus, Mars and some extrasolar terrestrial planets1 have a mass and radius that is consistent with a mass fraction of about 30% metallic core and 70% silicate mantle2. At the inner frontier
...

References

SHOWING 1-10 OF 33 REFERENCES

A rocky composition for an Earth-sized exoplanet

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.

Kepler-36: A Pair of Planets with Neighboring Orbits and Dissimilar Densities

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.

ALL SIX PLANETS KNOWN TO ORBIT KEPLER-11 HAVE LOW DENSITIES

The Kepler-11 planetary system contains six transiting planets ranging in size from 1.8 to 4.2 times the radius of Earth. Five of these planets orbit in a tightly packed configuration with periods

A PLATEAU IN THE PLANET POPULATION BELOW TWICE THE SIZE OF EARTH

We carry out an independent search of Kepler photometry for small transiting planets with sizes 0.5–8.0 times that of Earth and orbital periods between 5 and 50 days, with the goal of measuring the

A super-Earth transiting a nearby low-mass star

Observations of the transiting planet GJ’1214b are reported, finding that the planetary mass and radius are consistent with a composition of primarily water enshrouded by a hydrogen–helium envelope that is only 0.05% of the mass of the planet.

MINIMUM RADII OF SUPER-EARTHS: CONSTRAINTS FROM GIANT IMPACTS

The detailed interior structure models of super-Earth planets show that there is degeneracy in the possible bulk compositions of a super-Earth at a given mass and radius, determined via radial

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.

An abundance of small exoplanets around stars with a wide range of metallicities

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.

TRANSITS AND OCCULTATIONS OF AN EARTH-SIZED PLANET IN AN 8.5 hr ORBIT

We report the discovery of an Earth-sized planet (1.16 ± 0.19 R⊕) in an 8.5 hr orbit around a late G-type star (KIC 8435766, Kepler-xx). The object was identified in a search for short-period planets

THE OCCURRENCE RATE OF SMALL PLANETS AROUND SMALL STARS

We use the optical and near-infrared photometry from the Kepler Input Catalog to provide improved estimates of the stellar characteristics of the smallest stars in the Kepler target list. We find