Abstract
A study is presented of how the upper atmosphere of a planet is heated by extreme radiation from the parent star, depending on the distribution of the radiation flux in the soft X-ray and extreme ultraviolet (EUV) ranges. Calculations are performed to find the efficiency of heating by stellar X-ray to EUV radiation in a hydrogen-dominated upper atmosphere for the extrasolar gas giant HD 209458b. It is shown that heating efficiency by extreme stellar UV radiation in a hydrogen-dominated upper atmosphere does not exceed 20–25% at the main thermospheric heights given that the calculation takes into account the photoelectron impact. It is found that an increase in the X-ray flux by several orders of magnitude leads to a slight decrease in the heating efficiency.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Baraffe, I., Selsis, F., Chabrier, G., Barman, T.S., Allard, F., Hauschildt, P.H., and Lammer, H., The effect of evap-oration on the evolution of close-in giant planets, Astron. Astrophys., 2004, vol. 419, pp. L13–L16.
Bisikalo, D., Kaygorodov, P., Ionov, D., Shematovich, V., Lammer, H., and Fossati, L., 3D gas dynamic simula-tion of the interaction between the exoplanet WASP-12b and its host star, Astrophys. J., 2013a, vol. 764, p. 19.
Bisikalo, D.V., Kaigorodov, P.V., Ionov, D.E., and Shema-tovich, V.I., Types of gaseous envelopes of “hot Jupiter” exoplanets, Astron. Rep., 2013b, vol. 90, p. 715.
Chassefière, E., Hydrodynamic escape of hydrogen from a hot water-rich atmosphere: the case of Venus, J. Geo-phys. Res., 1996, vol. 101, pp. 26039–26056.
Davis, T.A. and Wheatley, P.J., Evidence for a lost popula-tion of close-in exoplanets, Mon. Notic. Roy. Astron. Soc., 2009, vol. 396, pp. 1012–1017.
Ehrenreich, D. and Dèsert, J.-M., Mass-loss rates for tran-siting exoplanets, Astron. Astrophys., 2011, vol. 529, p. A136.
Erkaev, N.V., Lammer, H., Odert, P., Kulikov, Yu.N., Kisly-akova, K.G., Khodachenko, M.L., Güdel, M., Hanslmeier, A., and Biernat, H., XUV-exposed, non-hydrostatic hydrogen-rich upper atmospheres of terres-trial planets. Pt. I: Atmospheric expansion and thermal escape, Astrobiology, 2013, vol. 13, pp. 1011–1029.
Garvey, R.H. and Green, A.E.S., Energy-apportionment techniques based upon detailed atomic cross sections, Phys. Rev. A, 1976, vol. 14, pp. 946–953.
Garvey, R.H., Porter, H.S., and Green, A.E.S., An analytic degradation spectrum for H2, J. Appl. Phys., 1977, vol. 48, pp. 190–193.
Hubbard, W.B., Hattori, M.F., Burrows, A., and Hubeny, I., A mass function constraint on extrasolar giant planet evaporation rates, Astrophys. J., 2007a, vol. 658, pp. L59–L62.
Hubbard, W.B., Hattori, M.F., Burrows, A., Hubeny, I., and Sudarsky, D., Effects of mass loss for highly-irradi-ated giant planets, Icarus, 2007b, vol. 187, pp. 358–364.
Huebner, W.F., Keady, J.J., and Lyon, S.P., Solar photorates for planetary atmospheres and atmospheric pollutants, Astrophys. Space Sci., 1992, vol. 195, pp. 1–294.
Ionov, D.E., Bisikalo, D.V., Shematovich, V.I., and Hubert, B., Ionization fraction in the thermosphere of the exoplanet HD209458b, Solar Syst. Res., 2014, vol. 48, no. 2, pp. 105–112.
Jackman, C.H., Garvey, R.H., and Green, A.E.S., Electron impact on atmospheric gases. I–updated cross sec-tions, J. Geophys. Res., 1977, vol. 82, pp. 5081–5090.
Jackson, B., Miller, N., Barnes, R., Raymond, S.N., Fort-ney, J.J., and Greenberg, R., The roles of tidal evolution and evaporative mass loss in the origin of CoRoT-7 b, Mon. Notic. Roy. Astron. Soc., 2010, vol. 407, pp. 910–922.
Jackson, A.P., Davis, T.A., and Wheatley, P.J., The coronal X-ray-age relation and its implications for the evapora-tion of exoplanets, Mon. Notic. Roy. Astron. Soc., 2012, vol. 422, pp. 2024–2043.
Kawahara, H., Hirano, T., Kurosaki, K., Ito, Y., and Ikoma, M., Starspots-transit depth relation of the evap-orating planet candidate KIC 12557548b, Astrophys. J., 2013, vol. 776, p. L6.
Kislyakova, K.G., Lammer, H., Holmstrom, M., Panchenko, M., Odert, P., Erkaev, N.V., Leitzinger, M., Khodachenko, M.L., Kulikov, Yu.N., Güdel, M., and Hanslmeier, A., XUV-exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets. Pt. II: Hydrogen coronae and ion escape, Astrobiology, 2013, vol. 13, pp. 1030–1048.
Koskinen, T.T., Harris, M.J., Yelle, R., and Lavvas, P., The escape of heavy atoms from the ionosphere of HD209458b. I. A photochemical-dynamical model of the thermosphere, Icarus, 2013, vol. 226, pp. 1678–1694.
Ksanfomaliti, L.V., On the nature of the object HD209458b: conclusions drawn from comparison of experimental and theoretical data, Solar Syst. Res., 2004a, vol. 38, no. 4, pp. 300–308.
Ksanfomality, L.V., Regularity of extrasolar planetary sys-tems and the role of the star metallicity in the formation of planets (review), Solar Syst. Res., 2004b, vol. 38, no. 5, pp. 372–382.
Kurokawa, H. and Kaltenegger, L., Atmospheric mass-loss and evolution of short-period exoplanets: the examples of CoRoT-7b and Kepler-10b, Mon. Notic. Roy. Astron. Soc., 2013, vol. 433, pp. 3239–3245.
Lammer, H., Selsis, F., Ribas, I., Guinan, E.F., Bauer, S.J., and Weiss, W.W., Atmospheric loss of exoplanets result-ing from stellar X-ray and extreme-ultraviolet heating, Astrophys. J., 2003, vol. 598, pp. L121–L126.
Lammer, H., Odert, P., Leitzinger, M., Khodachenko, M.L., Panchenko, M., Kulikov, Yu.N., Zhang, T.L., Licht-enegger, H.I.M., Erkaev, N.V., Wuchterl, G., Micela, G., Penz, T., Biernat, H.K., Weingrill, J., Steller, M., Ottacher, H., Hasiba, J., and Hanslmeier, A., Determining the mass loss limit for close-in exoplanets: what can we learn from transit observations?, Astron. Astrophys., 2009, vol. 506, pp. 399–410.
Lammer, H., Erkaev, N.V., Odert, P., Kislyakova, K.G., Leitzinger, M., and Khodachenko, M.L., Probing the blow-off criteria of hydrogen-rich ‘super-Earths’, Mon. Notic. Roy. Astron. Soc., 2013, vol. 430, pp. 1247–1256.
Lecavelier des Etangs, A., Vidal-Madjar, A., McConnell, J.C., and Hébrard, G., Atmospheric escape from hot Jupi-ters, Astron. Astrophys., 2004, vol. 418, pp. L1–L4.
Lecavelier des Etangs, A., A diagram to determine the evap-oration status of extrasolar planets, Astron. Astrophys., 2007, vol. 461, pp. 1185–1193.
Leitzinger, M., Odert, P., Kulikov, Yu.N., Lammer, H., Wuchterl, G., Penz, T., Guarcello, M.G., Micela, G., Khodachenko, M.L., Weingrill, J., Hanslmeier, A., Biernat, H.K., and Schneider, J., Could CoRoT-7b and Kepler-10b be remnants of evaporated gas or ice giants?, Planet. Space Sci., 2011, vol. 59, pp. 1472–1481.
Linsky, J.L. and Güdel, M., Exoplanet host star radiation and plasma environment, in Characterizing Stellar and Exoplanetary eEnvironments, Lammer, H. and Kho-dachenko, M., Eds., Springer, Astrophys. and Space Sci. Lib., 2015, vol. 411, pp.105–136.
Lissauer, J.J., Fabrycky, D.C., Ford, E.B., and 36 coau-thors, A closely packed system of low-mass, low-den-sity planets transiting Kepler-11, Nature, 2011, vol. 470, pp. 53–58.
Lopez, E.D., Fortney, J.J., and Miller, N., How thermal evolution and mass-loss sculpt populations of super-Earths and sub-Neptunes: application to the Kepler-11 system and beyond, Astrophys. J., 2012, vol. 761, p. id. 59.
Lopez, E.D. and Fortney, J.J., The role of core mass in con-trolling evaporation: the Kepler radius distribution and the Kepler-36 density dichotomy, Astrophys. J., 2013, vol. 776, p. id. 2.
Marov, M.Ya., Shematovich, V.I., and Bisikalo, D.V., Non-equilibrium processes in the planetary and cometary atmospheres. A kinetic approach to modeling, Space Sci. Rev., 1996, vol. 76, pp. 1–200.
Murray-Clay, R.A., Chiang, E.I., and Murray, N., Atmo-spheric escape from hot Jupiters, Astrophys. J., 2009, vol. 693, pp. 23–42.
Penz, T., Erkaev, N.V., Kulikov, Yu.N., Langmayr, D., Lammer, H., Micela, G., Cecchi-Pestellini, C., Bier-nat, H.K., Selsis, F., Barge, P., Deleuil, M., and Léger, A., Mass loss from “hot Jupiters”—implications for CoRoT discoveries. Pt. II: Long time thermal atmo-spheric evaporation modeling, Planet. Space Sci., 2008, vol. 56, pp. 1260–1272.
Sanz-Forcada, J., Ribas, I., Micela, G., Pollock, A.M.T., García-Álvarez, D., Solano, E., and Eiroa, C., A sce-nario of planet erosion by coronal radiation, Astron. Astrophys., 2010, vol. 511, p. id. L8.
Sanz-Forcada, J., Micela, G., Ribas, I., Pollock, A.M.T., Eiroa, C., Velasco, A., Solano, E., and García-Álvarez, D., Estimation of the xuv radiation onto close planets and their evaporation, Astron. Astrophys., 2011, vol. 532, p. id. A6.
Shaikhislamov, I.F., Khodachenko, M.L., Sasunov, Yu.L., Lammer, H., Kislyakova, K.G., and Erkaev, N.V., Atmosphere expansion and mass loss of close-orbit giant exoplanets heated by stellar XUV. I. Modeling of hydrodynamic escape of upper atmospheric material, Astrophys. J., 2014, vol. 795, p. id. 132.
Shematovich, V.I., Bisikalo, D.V., Gérard, J.-C., Cox, C., Bougher, S.W., and Leblanc, F., Monte Carlo model of electron transport for the calculation of Mars dayglow emissions, J. Geophys. Res., 2008, vol. 113, p. E02011.
Shematovich, V.I., Supratermal hydrogen produced by the disassociation of molecular hedrogen in the extended atmosphere of exoplanet HD209458b, Solar Syst. Res., 2010, vol. 44, no. 2, pp. 96–103.
Shematovich, V.I., Ionov, D.E., and Lammer, H., Heating efficiency in hydrogen-dominated upper atmospheres, Astron. Astrophys., 2014, vol. 571, p. id. A94.
Valencia, D., Guillot, T., Parmentier, V., and Freedman, R.S., Bulk composition of GJ1214b and other sub-neptune exoplanets, Astrophys. J., 2013, vol. 775, p. id. 10.
Vidal-Madjar, A., Lecavelier des Etangs, A., Desert, J.-M., Ballester, G.E., Ferlet, R., Hé brard, G., and Mayor, M., An extended upper atmosphere around the extrasolar planet HD209458b, Nature, 2003, vol. 422, pp. 143–146.
Watson, A.J., Donahue, T.M., and Walker, J.C.G., The dynamics of a rapidly escaping atmosphere–applica-tions to the evolution of Earth and Venus, Icarus, 1981, vol. 48, pp. 15–31.
Wu, Y. and Lithwick, Y., Density and eccentricity of Kepler planets, Astrophys. J., 2013, vol. 772, p. id. 74.
Yelle, R., Aeronomy of extra-solar giant planets at small orbital distances, Icarus, 2004, vol. 170, pp. 167–179.
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © D.E. Ionov, V.I. Shematovich, 2015, published in Astronomicheskii Vestnik, 2015, Vol. 49, No. 5, pp. 373–379.
Rights and permissions
About this article
Cite this article
Ionov, D.E., Shematovich, V.I. Hydrogen-dominated upper atmosphere of an exoplanet: Heating by stellar radiation from soft X-rays to extreme ultraviolet. Sol Syst Res 49, 339–345 (2015). https://doi.org/10.1134/S0038094615050056
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0038094615050056