Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-06-10T06:09:03.735Z Has data issue: false hasContentIssue false

The habitable zone for Earth-like exomoons orbiting Kepler-1625b

Published online by Cambridge University Press:  11 February 2019

Duncan H. Forgan*
Affiliation:
Centre for Exoplanet Science, SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
*
Author for correspondence: Duncan H. Forgan, E-mail:dhf3@st-andrews.ac.uk

Abstract

The recent announcement of a Neptune-sized exomoon candidate orbiting the Jupiter-sized object Kepler-1625b has forced us to rethink our assumptions regarding both exomoons and their host exoplanets. In this paper, I describe calculations of the habitable zone for Earth-like exomoons in the orbit of Kepler-1625b under a variety of assumptions. I find that the candidate exomoon, Kepler-1625b-i, does not currently reside within the exomoon habitable zone, but may have done so when Kepler-1625 occupied the main sequence. If it were to possess its own moon (a ‘moon–moon’) that was Earth-like, this could potentially have been a habitable world. If other exomoons orbit Kepler-1625b, then there are a range of possible semi-major axes/eccentricities that would permit a habitable surface during the main sequence phase, while remaining dynamically stable under the perturbations of Kepler-1625b-i. This is however contingent on effective atmospheric CO2 regulation.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2019 

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

Agol, E, Jansen, T, Lacy, B, Robinson, TD and Meadows, V (2015) The center of light: spec-troastrometric detection of exomoons. Astrophysical Journal 812, 5.Google Scholar
Berger, TA, Huber, D, Gaidos, E and van Saders, JL (2018) Revised radii of kepler stars and planets using gaia data release 2. Astrophysical Journal, p. in press.Google Scholar
Canup, RM and Ward, WR (2006) A common mass scaling for satellite systems of gaseous planets. Nature 441, 834839.Google Scholar
Cuntz, M (2014) S -Type And P -Type Habitability In Stellar Binary Systems: A Com- Prehensive Approach. I. Method And Applications. Astrophysical Journal 780, 14.Google Scholar
Dobos, V and Turner, EL (2015) Viscoelastic models of tidally heated exomoons. Astrophysical Journal 804, 41.Google Scholar
Domingos, RC, Winter, OC and Yokoyama, T (2006) Stable satellites around extrasolar giant planets. Monthly Notices of the Royal Astronomical Society 373, 12271234.Google Scholar
Farrell, BF (1990) Equable climate dynamics. Journal of Atmospheric Sciences 47, 29862995.Google Scholar
Forgan, D (2012) Oscillations in the habitable zone around α centauri B. Monthly Notices of the Royal Astronomical Society 422, 12411249.Google Scholar
Forgan, D (2016a) OBERON: OBliquity and Energy Balance Run On N Body Systems (First Release), https://zenodo.org/record/61236.Google Scholar
Forgan, D (2016b) Milankovitch cycles of terrestrial planets in binary star systems. Monthly Notices of the Royal Astronomical Society 463, 27682780.Google Scholar
Forgan, D (2017) On the feasibility of exomoon detection via exoplanet phase curve spectral contrast. Monthly Notices of the Royal Astronomical Society 470, 416426.Google Scholar
Forgan, D and Dobos, V (2016) Exomoon climate models with the carbonate-silicate cycle and viscoelastic tidal heating. Monthly Notices of the Royal Astronomical Society 457, 12331241.Google Scholar
Forgan, D and Kipping, D (2013) Dynamical effects on the habitable zone for Earth-like exomoons. Monthly Notices of the Royal Astronomical Society 432, 29943004.Google Scholar
Forgan, D and Yotov, V (2014) The effect of planetary illumination on climate modelling of Earth-like exomoons. Monthly Notices of the Royal Astronomical Society 441, 35133523.Google Scholar
Haqq-Misra, J and Heller, R (2018) Exploring exomoon atmospheres with an idealized general circulation model. Monthly Notices of the Royal Astronomical Society 479, 34773489.Google Scholar
Heller, R (2012) Exomoon habitability constrained by energy flux and orbital stability. Astronomy & Astrophysics 545, L8.Google Scholar
Heller, R (2017) The nature of the giant exomoon candidate Kepler-1625 b-i. Astronomy & Astrophysics 610, A39.Google Scholar
Heller, R and Barnes, R (2013) Exomoon habitability constrained by illumination and tidal heating. Astrobiology 13, 1846.Google Scholar
Heller, R and Barnes, R (2015) Runaway greenhouse effect on exomoons due to irradiation from hot, young giant planets. International Journal of Astrobiology 14, 335343.Google Scholar
Heller, R and Pudritz, R (2015) Water ice lines and the formation of giant moons around super-jovian planets. The Astrophysical Journal 806, 181.Google Scholar
Hinkel, NR and Kane, SR (2013) Habitability of exomoons at the hill or tidal locking radius. Astrophysical Journal 774, 27.Google Scholar
Iess, L, Stevenson, DJ, Parisi, M, Hemingway, D, Jacobson, RA, Lunine, JI, Nimmo, F, Armstrong, JW, Asmar, SW, Ducci, M and Tortora, P (2014) The gravity field and interior structure of enceladus. Science 344, 7880.Google Scholar
Kaltenegger, L and Haghighipour, N (2013) Calculating the babitable zone of binary star systems. I. S-type binaries. Astrophysical Journal 777, 165.Google Scholar
Mathur, S, Huber, D, Batalha, NM, Ciardi, DR, Bastien, FA, Bieryla, A, Buchhave, LA, Cochran, WD, Endl, M, Esquerdo, GA, Furlan, E, Howard, A, Howell, SB, Isaacson, H, Latham, DW, MacQueen, PJ and Silva, DR (2017) Revised stellar properties of kepler targets for the Q1-17 (DR25) transit detection run. The Astrophysical Journal Supplement Series 229, 30.Google Scholar
Mayor, M and Queloz, D (1995) A Jupiter-mass companion to asolar-typestar. Nature 378, 355359.Google Scholar
Melosh, H, Ekholm, A, Showman, A and Lorenz, R (2004) The temperature of Europa's subsurface water ocean. Icarus 168, 498502.Google Scholar
Mosqueira, I and Estrada, PR (2003a) Formation of the regular satellites of giant planets in an extended gaseous nebula I: subnebula model and accretion of satellites. Icarus 163, 198231.Google Scholar
Mosqueira, I and Estrada, PR (2003b) Formation of the regular satellites of giant planets in an extended gaseous nebula II: satellite migration and survival. Icarus 163, 232255.Google Scholar
North, GR and Coakley, JA (1979) A seasonal climate model for earth. In Evolution of Planetary Atmospheres and Climatology of the Earth. p. 249.Google Scholar
North, G, Cahalan, R and Coakley, J (1981) Energy balance climate models. Reviews of Geophysics and Space Physics 19, 91121.Google Scholar
North, GR, Mengel, JG and Short, DA (1983) Simple energy balance model resolving the seasons and the continents: Application to the astronomical theory of the ice ages. Journal of Geophysical Research 88, 6576.Google Scholar
Peale, S, Cassen, P and Reynolds, R (1980) Tidal dissipation, orbital evolution, and the nature of Saturn's inner satellites. Icarus 43, 6572.Google Scholar
Rodenbeck, K, Heller, R, Hippke, M and Gizon, L (2018) Revisiting the exomoon candidate signal around Kepler-1625 b. Astronomy & Astrophysics 617, A49.Google Scholar
Saur, J, Duling, S, Roth, L, Jia, X, Strobel, DF, Feldman, PD, Christensen, UR, Retherford, KD, McGrath, MA, Musacchio, F, Wennmacher, A, Neubauer, FM, Simon, S and Hartkorn, O (2015) The search for a subsurface ocean in Ganymede with Hubble Space Telescope observations of its auroral ovals. Journal of Geophysical Research: Space Physics 120, 17151737.Google Scholar
Scharf, CA (2006) The Potential for Tidally Heated Icy and Temperate Moons around Exoplanets. Astrophysical Journal 648, 11961205.Google Scholar
Shields, AL, Meadows, VS, Bitz, CM, Pierrehumbert, RT, Joshi, MM and Robinson, TD (2013) The effect of host star spectral energy distribution and ice-albedo feedback on the climate of extrasolar planets. Astrobiology 13, 715739.Google Scholar
Spiegel, DS, Menou, K and Scharf, CA (2008) Habitable climates. Astrophysical Journal 681, 16091623.Google Scholar
Spiegel, DS, Raymond, SN, Dressing, CD, Scharf, CA and Mitchell, JL (2010) Generalized milankovitch cycles and long-term climatic habitability. Astrophysical Journal 721, 13081318.Google Scholar
Teachey, A and Kipping, DM (2018) Evidence for a large exomoon orbiting Kepler-1625b. Science Advances 4, eaav1784.Google Scholar
Teachey, A, Kipping, DM and Schmitt, AR (2017) On the dearth of galilean analogs in kepler, and the exomoon candidate kepler-1625b I. Astronomical Journal 155, 36.Google Scholar
Thomas, P, Tajeddine, R, Tiscareno, M, Burns, J, Joseph, J, Loredo, T, Helfenstein, P and Porco, C (2015) Enceladus's measured physical libration requires a global subsurface ocean. Icarus 264, 3747.Google Scholar
Vladilo, G, Murante, G, Silva, L, Provenzale, A, Ferri, G and Ragazzini, G (2013) The Habitable zone of earth-like planets with different levels of atmospheric pressure. Astrophysical Journal 767, 65.Google Scholar
Ward, WR and Canup, RM (2010) Circumplanetary disk formation. The Astronomical Journal 140, 11681193.Google Scholar
Williams, D and Kasting, J (1997) Habitable planets with high obliquities. Icarus 129, 254267.Google Scholar