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Steps towards eta-Earth, from Kepler data

Published online by Cambridge University Press:  02 October 2014

Wesley A. Traub
Wesley A. Traub*
Affiliation:
Jet Propulsion Laboratory, M/S 321-100, 4800 Oak Grove Dr. Pasadena, Pasadena, CA 91109, USA Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
*
e-mail: wtraub@jpl.nasa.gov
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Abstract

The goal of this paper is to take steps towards estimating the frequency of terrestrial planets in the habitable zones of their host stars, using planet counts from the Kepler mission. The method is to assume that an analytical form for the underlying distribution function, numerically simulate the observing procedure, compare the simulated and real observations, and iterate the model parameters to achieve convergence in the sense of least-squares. The underlying distribution can then be extrapolated to a region of interest, here the terrestrial habitable-zone range. In this regime (small radii, long periods), the instrument noise makes such detections essentially impossible below a fairly sharply defined threshold signal level. This threshold can be estimated from the existing data. By taking this cutoff into account, the distribution of planets, as a function of radius and period, can be estimated with minimal bias. Extending this distribution to terrestrial planets in habitable-zone orbits can yield an estimate of eta-sub-Earth.

Keywords

eta-EarthExoplanethabitable zoneKeplernoise estimationterrestrial planets
Type
Research Article
Information
International Journal of Astrobiology , Volume 14 , Issue 3 , July 2015 , pp. 359 - 363
Copyright
Copyright © Cambridge University Press 2014 

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