Origins of Life and Evolution of Biospheres

, Volume 46, Issue 4, pp 351–359 | Cite as

Which Type of Planets do We Expect to Observe in the Habitable Zone?

  • Vardan AdibekyanEmail author
  • Pedro Figueira
  • Nuno C. Santos


We used a sample of super-Earth-like planets detected by the Doppler spectroscopy and transit techniques to explore the dependence of orbital parameters of the planets on the metallicity of their host stars. We confirm the previous results (although still based on small samples of planets) that super-Earths orbiting around metal-rich stars are not observed to be as distant from their host stars as we observe their metal-poor counterparts to be. The orbits of these super-Earths with metal-rich hosts usually do not reach into the Habitable Zone (HZ), keeping them very hot and inhabitable. We found that most of the known planets in the HZ are orbiting their GK-type hosts which are metal-poor. The metal-poor nature of planets in the HZ suggests a high Mg abundance relative to Si and high Si abundance relative to Fe. These results lead us to speculate that HZ planets might be more frequent in the ancient Galaxy and had compositions different from that of our Earth.


Planet composition Stellar abundances Habitability Planetary orbits 



This work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grant UID/FIS/04434/2013. V.A. acknowledges the support from the Fundação para a Ciência e Tecnologia, FCT (Portugal) in the form of the grant SFRH/BPD/70574/2010. P.F. and N.C.S. also acknowledge the support from FCT through Investigador FCT contracts of reference IF/01037/2013 and IF/00169/2012, respectively, and POPH/FSE (EC) by FEDER funding through the program “Programa Operacional de Factores de Competitividade - COMPETE”. PF further acknowledges support from Fundação para a Ciência e a Tecnologia (FCT) in the form of an exploratory project of reference IF/01037/2013CP1191/CT0001. This work results within the collaboration of the COST Action TD 1308. We would like to thank João Faria for his interesting comments and suggestions.


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Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • Vardan Adibekyan
    • 1
    Email author
  • Pedro Figueira
    • 1
  • Nuno C. Santos
    • 1
    • 2
  1. 1.Instituto de Astrofísica e Ciências do EspaçoUniversidade do Porto, CAUPPortoPortugal
  2. 2.Departamento de Física e Astronomia, Faculdade de CiênciasUniversidade do PortoPortoPortugal

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