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Stellar activity effects on the atmospheric escape of hot Jupiters

Published online by Cambridge University Press:  20 January 2023

Hiroto Mitani
Affiliation:
Department of Physics, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 email: [email protected]
Riouhei Nakatani
Affiliation:
RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Naoki Yoshida
Affiliation:
Department of Physics, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 email: [email protected] Kavli Institute for the Physics and Mathematics of the Universe (WPI), UT Institutes for Advanced Study, The University of Tokyo, Kashiwa, Chiba 277-8583, Japan Research Center for the Early Universe, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033
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Abstract

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Transit observations have revealed the existence of atmospheric escape in several hot Jupiters. High energy photons from the host star heat the upper atmosphere and drive the hydrodynamic escape. The escaping atmosphere can interact with the stellar wind from the host star. We run radiation hydrodynamics simulations with non-equilibrium chemistry to investigate the wind effects on the escape and the transit signature. Our simulations follow the planetary outflow driven by the photoionization heating and the wind interaction in a dynamically coupled, self-consistent manner. We show that the planetary mass-loss rate is almost independent of the wind strength, which however affects the Ly-α transit depth considerably. But the Hα transit depth is almost independent of the wind strength because it is largely caused by the lower hot layer. We argue that observations of both lines can solve the degeneracy between the EUV flux from the host and the wind strength.

Type
Contributed Paper
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
© The Author(s), 2023. Published by Cambridge University Press on behalf of International Astronomical Union

References

Anninos, P., Zhang, Y., Abel, T., & Norman, M. L. 1997, Cosmological hydrodynamics with multi-species chemistry and nonequilibrium ionization and cooling. New Astron., 2(3), 209224.10.1016/S1384-1076(97)00009-2CrossRefGoogle Scholar
Bisikalo, D., Kaygorodov, P., Ionov, D., Shematovich, V., Lammer, H., & Fossati, L. 2013, Threedimensional Gas Dynamic Simulation of the Interaction between the Exoplanet WASP-12b and its Host Star. ApJ, 764(1), 19.10.1088/0004-637X/764/1/19CrossRefGoogle Scholar
Bisikalo, D. V., Shematovich, V. I., Cherenkov, A.A., Fossati, L., & Möstl, C. 2018, Atmospheric Mass Loss from Hot Jupiters Irradiated by Stellar Superflares. ApJ, 869(2), 108.CrossRefGoogle Scholar
Carolan, S., Vidotto, A. A., Villarreal D’Angelo, C., & Hazra, G. 2021, Effects of the stellar wind on the Ly α transit of close-in planets. MNRAS, 500(3), 33823393.CrossRefGoogle Scholar
Cherenkov, A. A., Bisikalo, D. V., & Kosovichev, A. G. 2018, Influence of stellar radiation pressure on flow structure in the envelope of hot-Jupiter HD 209458b. MNRAS, 475(1), 605613.CrossRefGoogle Scholar
Christie, D., Arras, P., & Li, Z.-Y. 2013, Hα Absorption in Transiting Exoplanet Atmospheres. ApJ, 772(2), 144.10.1088/0004-637X/772/2/144CrossRefGoogle Scholar
Ehrenreich, D., Bourrier, V., Wheatley, P. J., Lecavelier des Etangs, A., Hébrard, G., Udry, S., Bonfils, X., Delfosse, X., Désert, J.-M., Sing, D. K., & Vidal-Madjar, A. 2015, A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b. Nature, 522(7557), 459461.10.1038/nature14501CrossRefGoogle ScholarPubMed
Feinstein, A. D., Montet, B. T., Ansdell, M., Nord, B., Bean, J. L., Günther, M. N., Gully-Santiago, M. A., & Schlieder, J. E. 2020, Flare Statistics for Young Stars from a Convolutional Neural Network Analysis of TESS Data. AJ, 160(5), 219.CrossRefGoogle Scholar
Fulton, B. J., Petigura, E. A., Howard, A. W., Isaacson, H., Marcy, G. W., Cargile, P. A., Hebb, L., Weiss, L. M., Johnson, J. A., Morton, T. D., Sinukoff, E., Crossfield, I. J. M., & Hirsch, L. A. 2017, The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets. AJ, 154(3), 109.Google Scholar
Maehara, H., Notsu, Y., Notsu, S., Namekata, K., Honda, S., Ishii, T. T., Nogami, D., & Shibata, K. 2017, Starspot activity and superflares on solar-type stars. PASJ, 69(3), 41.CrossRefGoogle Scholar
Maehara, H., Shibayama, T., Notsu, Y., Notsu, S., Nagao, T., Honda, S., Nogami, D., & Shibata, K. Superflares on Late-Type Stars. In Haghighipour, N., editor, Formation, Detection, and Characterization of Extrasolar Habitable Planets 2014, volume 293, pp. 393–395.CrossRefGoogle Scholar
McCann, J., Murray-Clay, R. A., Kratter, K., & Krumholz, M. R. 2019, Morphology of Hydrodynamic Winds: A Study of Planetary Winds in Stellar Environments. ApJ, 873(1), 89.CrossRefGoogle Scholar
Mignone, A., Bodo, G., Massaglia, S., Matsakos, T., Tesileanu, O., Zanni, C., & Ferrari, A. 2007, PLUTO: A Numerical Code for Computational Astrophysics. ApJS, 170(1), 228242.10.1086/513316CrossRefGoogle Scholar
Mitani, H., Nakatani, R., & Yoshida, N. 2021, Stellar Wind Effect on the Atmospheric Escape of Hot Jupiters. arXiv e-prints, arXiv:2111.00471.Google Scholar
Murray-Clay, R. A., Chiang, E. I., & Murray, N. 2009, Atmospheric Escape From Hot Jupiters. ApJ, 693(1), 2342.CrossRefGoogle Scholar
Nakatani, R., Hosokawa, T., Yoshida, N., Nomura, H., & Kuiper, R. 2018, Radiation Hydrodynamics Simulations of Photoevaporation of Protoplanetary Disks by Ultraviolet Radiation: Metallicity Dependence. ApJ, 857(1), 57.CrossRefGoogle Scholar
Osterbrock, D. E. & Ferland, G. J. 2006,. Astrophysics of gaseous nebulae and active galactic nuclei. Spitzer, L. 1978,. Physical processes in the interstellar medium.Google Scholar
Szabó, G. M. & Kiss, L. L. 2011, A Short-period Censor of Sub-Jupiter Mass Exoplanets with Low Density. ApJ, 727(2), L44.10.1088/2041-8205/727/2/L44CrossRefGoogle Scholar
Vidal-Madjar, A., Lecavelier des Etangs, A., Désert, J. M., Ballester, G. E., Ferlet, R., Hébrard, G., & Mayor, M. 2003, An extended upper atmosphere around the extrasolar planet HD209458b. Nature, 422(6928), 143146.10.1038/nature01448CrossRefGoogle ScholarPubMed
Vidotto, A. A. & Cleary, A. 2020, Stellar wind effects on the atmospheres of close-in giants: a possible reduction in escape instead of increased erosion. MNRAS, 494(2), 24172428.10.1093/mnras/staa852CrossRefGoogle Scholar
Zhilkin, A. G., Bisikalo, D. V., & Kaygorodov, P. V. 2020, Coronal Mass Ejection Effect on Envelopes of Hot Jupiters. Astronomy Reports, 64(2), 159167.10.1134/S1063772920020055CrossRefGoogle Scholar