Variability in the atmosphere of the hot giant planet HAT-P-7 b

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Figure 1: Variation in peak offset of HAT-P-7 b phase curve with time.
Figure 2: Individual phase curves, with best-fitting model.
Figure 3: Model outputs giving positive and negative Θ values.
Figure 4: Contour map of Θ variations.


  1. 1

    Knutson, H. A., Charbonneau, D., Allen, L. E., Burrows, A. & Megeath, S. T. The 3.6–8.0 μm broadband emission spectrum of HD 209458b: Evidence for an atmospheric temperature inversion. Astrophys. J. 673, 526–531 (2008).

    Article  ADS  Google Scholar 

  2. 2

    Snellen, I. A. G., de Mooij, E. J. W. & Albrecht, S. The changing phases of extrasolar planet CoRoT-1b. Nature 459, 543–545 (2009).

    Article  ADS  Google Scholar 

  3. 3

    Artigau, É., Bouchard, S., Doyon, R. & Lafrenière, D. Photometric variability of the T2.5 brown dwarf SIMP J013656.5+093347: Evidence for evolving weather patterns. Astrophys. J. 701, 1534–1539 (2009).

    Article  ADS  Google Scholar 

  4. 4

    Radigan, J. et al. Large-amplitude variations of an L/T transition brown dwarf: Multi-wavelength observations of patchy, high-contrast cloud features. Astrophys. J. 750, 105 (2012).

    Article  ADS  Google Scholar 

  5. 5

    Esteves, L. J., de Mooij, E. J. W. & Jayawardhana, R. Optical phase curves of Kepler exoplanets. Astrophys. J. 772, 51 (2013).

    Article  ADS  Google Scholar 

  6. 6

    Esteves, L. J., de Mooij, E. J. W. & Jayawardhana, R. Changing phases of alien worlds: Probing atmospheres of Kepler planets with high-precision photometry. Astrophys. J. 804, 150 (2015).

    Article  ADS  Google Scholar 

  7. 7

    Pál, A. et al. HAT-P-7b: An extremely hot massive planet transiting a bright star in the Kepler field. Astrophys. J. 680, 1450–1456 (2008).

    Article  ADS  Google Scholar 

  8. 8

    Borucki, W. J. et al. Kepler planet-detection mission: Introduction and first results. Science 327, 977–980 (2010).

    Article  ADS  Google Scholar 

  9. 9

    Wong, I. et al. 3.6 and 4.5 μm Spitzer phase curves of the highly-irradiated hot Jupiters WASP-19b and HAT-P-7b. Astrophys. J. 823, 122 (2016).

    Article  ADS  Google Scholar 

  10. 10

    Christiansen, J. L. et al. Studying the atmosphere of the exoplanet Hat-P-7b via secondary eclipse measurements with Epoxi, Spitzer, and Kepler. Astrophys. J. 710, 97–104 (2010).

    Article  ADS  Google Scholar 

  11. 11

    Borucki, W. J. et al. Kepler’s optical phase curve of the exoplanet HAT-P-7b. Science 325, 709–709 (2009).

    Article  ADS  Google Scholar 

  12. 12

    Welsh, W. F. et al. The discovery of ellipsoidal variations in the Kepler light curve of Hat-P-7. Astrophys. J. Lett. 713, L145–L149 (2010).

    Article  ADS  Google Scholar 

  13. 13

    von Paris, P., Gratier, P., Bordé, P. & Selsis, F. Inferring heat recirculation and albedo for exoplanetary atmospheres: Comparing optical phase curves and secondary eclipse data. Astron. Astrophys. 587, A149 (2016).

    Article  ADS  Google Scholar 

  14. 14

    Faigler, S. & Mazeh, T. BEER analysis of Kepler and CoRoT light curves. II. Evidence for superrotation in the phase curves of three Kepler hot Jupiters. Astrophys. J. 800, 73 (2015).

    Article  ADS  Google Scholar 

  15. 15

    Showman, A. P. & Polvani, L. M. Equatorial superrotation on tidally locked exoplanets. Astrophys. J. 738, 71 (2011).

    Article  ADS  Google Scholar 

  16. 16

    Fromang, S., Leconte, J. & Heng, K. Shear-driven instabilities and shocks in the atmospheres of hot Jupiters. Astron. Astrophys. 591, A144 (2016).

    Article  ADS  Google Scholar 

  17. 17

    Webber, M. W. et al. Effect of longitude-dependent cloud coverage on exoplanet visible wavelength reflected-light phase curves. Astrophys. J. 804, 94 (2015).

    Article  ADS  Google Scholar 

  18. 18

    Rauscher, E., Menou, K., Cho, J. Y.-K., Seager, S. & Hansen, B. M. S. On signatures of atmospheric features in thermal phase curves of hot Jupiters. Astrophys. J. 681, 1646–1652 (2008).

    Article  ADS  Google Scholar 

  19. 19

    Showman, A. P. et al. Atmospheric circulation of hot Jupiters: Coupled radiative-dynamical general circulation model simulations of HD 189733b and HD 209458b. Astrophys. J. 699, 564–584 (2009).

    Article  ADS  Google Scholar 

  20. 20

    Agol, E. et al. The climate of HD 189733b from fourteen transits and eclipses measured by Spitzer. Astrophys. J. 721, 1861–1877 (2010).

    Article  ADS  Google Scholar 

  21. 21

    Knutson, H. A. et al. 3.6 and 4.5 mm phase curves and evidence for non-equilibrium chemistry in the atmosphere of extrasolar planet HD 189733b. Astrophys. J. 754, 22 (2012).

    Article  ADS  Google Scholar 

  22. 22

    Demory, B.-O., Gillon, M., Madhusudhan, N. & Queloz, D. Variability in the super-Earth 55 Cnc e. Mon. Not. R. Astron. Soc. 455, 2018–2027 (2015).

    Article  ADS  Google Scholar 

  23. 23

    Gillon, M. et al. Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b. Astron. Astrophys. 471, L51–L54 (2007).

    Article  ADS  Google Scholar 

  24. 24

    Hu, R., Demory, B.-O., Seager, S., Lewis, N. & Showman, A. P. A semi-analytical model of visible-wavelength phase curves of exoplanets and applications to Kepler-7 B and Kepler-10 B. Astrophys. J. 802, 51 (2015).

    Article  ADS  Google Scholar 

  25. 25

    Parmentier, V., Fortney, J. J., Showman, A. P., Morley, C. V. & Marley, M. S. Transitions in the cloud composition of hot Jupiters. Preprint at (2016).

  26. 26

    Kataria, T. et al. The atmospheric circulation of a nine-hot-Jupiter sample: Probing circulation and chemistry over a wide phase space. Astrophys. J. 821, 9 (2016).

    Article  ADS  Google Scholar 

  27. 27

    Schwartz, J. C. & Cowan, N. B. Balancing the energy budget of short-period giant planets: Evidence for reflective clouds and optical absorbers. Mon. Not. R. Astron. Soc. 449, 4192–4203 (2015).

    Article  ADS  Google Scholar 

  28. 28

    Still, M. & Barclay, T. PyKE: Reduction and analysis of Kepler simple aperture photometry data. Astrophys. Source Code Lib. 1208.004 (2012).

  29. 29

    Oliphant, T. E. Python for scientific computing. Comput. Sci. Eng. 9, 10–20 (2007).

    Article  Google Scholar 

  30. 30

    Foreman-Mackey, D., Hogg, D. W., Lang, D. & Goodman, J. emcee: The MCMC hammer. Publ. Astron. Soc. Pacific 125, 306–312 (2013).

    Article  ADS  Google Scholar 

  31. 31

    Van Eylen, V., Lindholm Nielsen, M., Hinrup, B., Tingley, B. & Kjeldsen, H. Investigation of systematic effects in Kepler data: Seasonal variations in the light curve of HAT-P-7b. Astrophys. J. Lett. 774, L19 (2013).

    Article  ADS  Google Scholar 

  32. 32

    Lomb, N. R. Least-squares frequency analysis of unequally spaced data. Astrophys. Space Sci. 39, 447–462 (1976).

    Article  ADS  Google Scholar 

  33. 33

    Scargle, J. D. Studies in astronomical time series analysis. II. Statistical aspects of spectral analysis of unevenly spaced data. Astrophys. J. 263, 835 (1982).

    Article  ADS  Google Scholar 

  34. 34

    McQuillan, A., Mazeh, T. & Aigrain, S. Stellar rotation periods of the Kepler objects of interest: A dearth of close-in planets around fast rotators. Astrophys. J. Lett. 775, L11 (2013).

    Article  ADS  Google Scholar 

  35. 35

    Morris, B. M., Mandell, A. M. & Deming, D. Kepler’s optical secondary eclipse of HAT-P-7b and probable detection of planet-induced stellar gravity darkening. Astrophys. J. Lett. 764, L22 (2013).

    Article  ADS  Google Scholar 

  36. 36

    Lund, M. N. et al. Asteroseismic inference on the spin-orbit misalignment and stellar parameters of HAT-P-7. Astron. Astrophys. 570, A54 (2014).

    Article  Google Scholar 

  37. 37

    Cranmer, S. R., Bastien, F. A., Stassun, K. G. & Saar, S. H. Stellar granulation as the source of high-frequency flicker in Kepler light curves. Astrophys. J. 781, 124 (2014).

    Article  ADS  Google Scholar 

  38. 38

    Cowan, N. B. & Agol, E. A model for thermal phase variations of circular and eccentric exoplanets. Astrophys. J. 726, 82 (2010).

    Article  ADS  Google Scholar 

  39. 39

    Wakeford, H. R. et al. High temperature condensate clouds in super-hot Jupiter atmospheres. Mon. Not. R. Astron. Soc. Preprint available at (2016).

  40. 40

    Lodders, K. in Formation and Evolution of Exoplanets Ch. 8 (Wiley, 2010).

    Google Scholar 

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D.J.A. acknowledges funding from the European Union Seventh Framework programme (FP7/2007–2013) under grant agreement No. 313014 (ETAEARTH). E.d.M. acknowledges support from the Michael West Fellowship. This paper includes data collected by the Kepler mission. Funding for the Kepler mission is provided by the NASA Science Mission directorate. All of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and contracts.

Author information




D.J.A. obtained and detrended the data, developed and fit the phase curve models, implemented the atmospheric model, produced the figures and wrote the manuscript. E.d.M. developed the discussion, contributed to the tests performed to check the results, and tested the results with his own models. H.P.O. contributed to the phase curve model, and produced visual interpretations of the results. J.Ba. developed the discussion of the atmospheric processes behind the peak offset variations. J.Bl. provided the initial development of the phase curve model. N.F.S. contributed to development of the figures. All authors commented on the manuscript.

Corresponding author

Correspondence to D. J. Armstrong.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Information Guide

Captions for Supplementary Table 1, Supplementary Figures 1–9, Supplementary Video 1 and Dataset 1. (PDF 127 kb)

Supplementary Information

Supplementary Table 1, Supplementary Figures 1–9 and description of phase curve model. (PDF 2248 kb)

Supplementary Video 1

HAT-P-7 b dayside visualization. (MP4 1400 kb)

Dataset 1

Table with individual fit values. (CSV 50 kb)

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Armstrong, D., de Mooij, E., Barstow, J. et al. Variability in the atmosphere of the hot giant planet HAT-P-7 b. Nat Astron 1, 0004 (2017).

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