1. Atmospheric mass loss by stellar wind from planets around main sequence M stars
- Author
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Zendejas, J., Segura, A., and Raga, A.C.
- Subjects
Extrasolar planets -- Analysis ,Extrasolar planets -- Models ,Magnetic fields -- Analysis ,Magnetic fields -- Models ,Life on other planets -- Analysis ,Life on other planets -- Models ,Automated teller machines -- Analysis ,Automated teller machines -- Models ,Outer space -- Discovery and exploration ,Outer space -- Analysis ,Outer space -- Models ,Astronomy ,Earth sciences - Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2010.07.013 Byline: J. Zendejas (a), A. Segura (b), A.C. Raga (b) Keywords: Astrobiology; Atmospheres, Evolution; Extrasolar planets; Solar wind Abstract: We present an analytic model for the interaction between planetary atmospheres and stellar winds from main sequence M stars, with the purpose of obtaining a quick test-model that estimates the timescale for total atmospheric mass loss due to this interaction. Planets in the habitable zone of M dwarfs may be tidally locked and may have weak magnetic fields, because of this we consider the extreme case of planets with no magnetic field. The model gives the planetary atmosphere mass loss rate as a function of the stellar wind and planetary properties (mass, atmospheric pressure and orbital distance) and an entrainment efficiency coefficient [alpha]. We use a mixing layer model to explore two different cases: a time-independent stellar mass loss and a stellar mass loss rate that decreases with time. For both cases we consider planetary masses within the range of 1[right arrow]10M.sub.[direct sum] and atmospheric pressures with values of 1, 5 and 10atm. We apply our model to Venus by estimating its atmospheric mass loss rate by the interaction with the solar wind and compare our model with more detailed simulations. We find a good agreement between our results and the atmospheric mass loss obtained by more detailed models, and it is therefore appropriate for carrying out an exploration of the broad parameter space of exoplanetary systems. For the time-dependent case, planets without magnetic field in the habitable zone of M dwarfs with initial stellar mass losses of M.sub.w Author Affiliation: (a) Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, A.P. 70-264, 04510 D.F., Mexico (b) Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 D.F., Mexico Article History: Received 3 November 2009; Revised 13 July 2010; Accepted 14 July 2010
- Published
- 2010