Hostname: page-component-76fb5796d-x4r87 Total loading time: 0 Render date: 2024-04-26T23:06:16.827Z Has data issue: false hasContentIssue false
  • English
  • Français

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
Get access Rights & Permissions [Opens in a new window]

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 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Christiansen, J.L., Jenkins, J.M., Caldwell, D.A., Burke, C.J., Tennenbaum, P., Seader, S., Thompson, S.E., Barclay, T.S., Clarke, B.D., Li, J., Smith, J.C., Stumpe, M.C., Twicken, J.D. & Van Cleve, J. (2012). The derivation, properties, and value of Kepler's combined differential photometric precision. Publ. Astron. Soc. Pacific 124, 1279–1287.Google Scholar
Farmer, R., Kolb, U. & Norton, A.J. (2013). The true stellar parameters of the Kepler target list. Mon. Not. R. Astron. Soc. 433, 1133–1145.Google Scholar
Gray, D. (2005). The Observation and Analysis of Stellar Photospheres, 3rd edn. Cambridge University Press, New York, NY.Google Scholar
Huber, D. et al. (2014). Revised stellar properties of Kepler targets for the quarter 1–16 transit detection run. Astrophys. J. Suppl. 211, 18.Google Scholar
Kopparapu, R., Ramirez, R., Schottelkotte, J., Kasting, J., Domagal-Goldman, S. & Eymet, V. Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass, astro-ph, arXiv:1404.5292v1, 21 April 2014.Google Scholar
Verner, G.A. et al. (2011). Verification of the Kepler input catalog from asteroseismology of solar-type stars. Astrophys. J. Lett. 738, L28.Google Scholar