Kepler's first rocky planet: Kepler-10b

The Astrophysical Journal (Impact Factor: 5.99). 02/2011; 729(1). DOI: 10.1088/0004-637X/729/1/27
Source: arXiv


NASA's Kepler Mission uses transit photometry to determine the frequency of
earth-size planets in or near the habitable zone of Sun-like stars. The mission
reached a milestone toward meeting that goal: the discovery of its first rocky
planet, Kepler-10b. Two distinct sets of transit events were detected: 1) a 152
+/- 4 ppm dimming lasting 1.811 +/- 0.024 hours with ephemeris
T[BJD]=2454964.57375+N*0.837495 days and 2) a 376 +/- 9 ppm dimming lasting
6.86 +/- 0.07 hours with ephemeris T[BJD]=2454971.6761+N*45.29485 days.
Statistical tests on the photometric and pixel flux time series established the
viability of the planet candidates triggering ground-based follow-up
observations. Forty precision Doppler measurements were used to confirm that
the short-period transit event is due to a planetary companion. The parent star
is bright enough for asteroseismic analysis. Photometry was collected at
1-minute cadence for >4 months from which we detected 19 distinct pulsation
frequencies. Modeling the frequencies resulted in precise knowledge of the
fundamental stellar properties. Kepler-10 is a relatively old (11.9 +/- 4.5
Gyr) but otherwise Sun-like Main Sequence star with Teff=5627 +/- 44 K,
Mstar=0.895 +/- 0.060 Msun, and Rstar=1.056 +/- 0.021 Rsun. Physical models
simultaneously fit to the transit light curves and the precision Doppler
measurements yielded tight constraints on the properties of Kepler-10b that
speak to its rocky composition: Mpl=4.56 +/- 1.29 Mearth, Rpl=1.416 +/- 0.036
Rearth, and density=8.8 +/- 2.9 gcc. Kepler-10b is the smallest transiting
exoplanet discovered to date.

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Available from: Francois Fressin, Oct 10, 2015
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    • "These low densities indicate substantial envelopes of light gases such as H and He or possibly H 2 O and H. Could it be that these " super-Earths " could not lose their initial proto-atmospheres and that they are, in fact, " mini-Neptunes " ? In fact, the only observed " super-Earths " with higher densities which indicate rocky bodies such as the CoRoT-7b (Léger et al. 2009), , Kepler-10b (Batalha et al. 2011), Kepler-18b or Kepler-20b (Borucki et al. 2011) are much closer to their star, at a distance where really strong atmospheric escape is expected. "
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    ABSTRACT: In the past 15 years, astronomers have revealed that a significant fraction of the stars should harbor planets and that it is likely that terrestrial planets are abundant in our galaxy. Among these planets, how many are habitable, i.e. suitable for life and its evolution? These questions have been discussed for years and we are slowly making progress. Liquid water remains the key criterion for habitability. It can exist in the interior of a variety of planetary bodies, but it is usually assumed that liquid water at the surface interacting with rocks and light is necessary for the emergence of a life able to modify its environment and evolve. A first key issue is thus to understand the climatic conditions allowing surface liquid water assuming a suitable atmosphere. This have been studied with global mean 1D models which has defined the "classical habitable zone", the range of orbital distances within which worlds can maintain liquid water on their surfaces (Kasting et al. 1993). A new generation of 3D climate models based on universal equations and tested on bodies in the solar system is now available to explore with accuracy climate regimes that could locally allow liquid water. A second key issue is now to better understand the processes which control the composition and the evolution of the atmospheres of exoplanets, and in particular the geophysical feedbacks that seems to be necessary to maintain a continuously habitable climate. From that point of view, it is not impossible that the Earth's case may be special and uncommon.
    12/2012; 12(3). DOI:10.1017/S1473550413000128
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    • "Exoplanet surveys have already discovered the first rocky, strongly irradiated exoplanets: Corot 7b (Léger et al. 2009) and Kepler 10b (Batalha et al. 2011). A whole population of hot planets with minimum masses below 10 Earth masses, consistent with rocky planet models (super-Earths) has already been detected. "
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    ABSTRACT: A decade of exoplanet search has led to surprising discoveries, from giant planets close to their star, to planets orbiting two stars, all the way to the first extremely hot, rocky worlds with potentially permanent lava on their surfaces due to the star's proximity. Observation techniques have reached the sensitivity to explore the chemical composition of the atmospheres as well as physical structure of some detected gas planets and detect planets of less than 10 Earth masses (MEarth), the so-called super-Earths, among them some that may potentially be habitable. Three confirmed non-transiting planets, and several transiting Kepler planetary candidates, orbit in the habitable zone (HZ) of their host star. The detection and characterization of rocky and potentially Earth-like planets is approaching rapidly with future ground and space missions that can explore the planetary environments by analysing their atmosphere remotely. This paper discusses how to characterize a rocky exoplanet remotely.
    International Journal of Astrobiology 10/2012; 11(4):297-307. DOI:10.1017/S1473550412000134 · 1.45 Impact Factor
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    • "The first one to be discovered are on close-in orbits around their parent stars. Known terrestrial exoplanets can therefore be as hot as a few thousand K, such as Corot-7b [7] and Kepler-10b [1]. The detectability of any spectral features in exoplanetary atmospheres depends mainly on two main parameters: their chemical composition and their temperature profile. "
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    ABSTRACT: We have developed a photo-thermo-chemical model adapted to the study of the hot terrestrial atmospheres. Such a model is essential to interpret future observations and to predict the composition of hot extrasolar terrestrial planets. It is also important to understand the formation and the evolution of some of their key atmospheric species. We investigate here the effect of an increase of the temperature on the predicted abundances of some of these key species, such as ozone O3 and carbon dioxide CO2.
    European Planetary Science Congress 2012; 09/2012
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