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A pulsating white dwarf in an eclipsing binary


White dwarfs are the burnt-out cores of Sun-like stars and are the fate of 97 per cent of the stars in our Galaxy. The internal structure and composition of white dwarfs are hidden by their high gravities, which causes all elements apart from the lightest ones to settle out of their atmospheres. The most direct method of probing the inner structure of stars and white dwarfs in detail is via asteroseismology. Here we present a pulsating white dwarf in an eclipsing binary system, enabling us to place extremely precise constraints on the mass and radius of the white dwarf from the lightcurve, independent of the pulsations. This 0.325-solar-mass white dwarf—one member of the SDSS J115219.99+024814.4 system—will serve as a powerful benchmark with which to constrain empirically the core composition of low-mass stellar remnants and to investigate the effects of close binary evolution on the internal structure of white dwarfs.

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Fig. 1: Trailed spectrogram of the Hα line of SDSS J1152+0248.
Fig. 2: HiPERCAM high-speed lightcurves of SDSS J1152+0248 with model fits overplotted.
Fig. 3: SED of SDSS J1152+0248 (red points are GALEX, SDSS and UKIDSS measurements) with best-fit model spectrum (black line and blue squares).
Fig. 4: The pulsations of the cool white dwarf in SDSS J1152+0248.
Fig. 5: Constraints on the masses and radii of the white dwarfs in SDSS J1152+0248.

Data availability

The raw ( and reduced ( X-shooter data presented in this paper are available from the European Southern Observatory. Raw and reduced HiPERCAM data are available from the Gran Telescopio Canarias here: These data can also be obtained from the corresponding author upon reasonable request.

Code availability

The X-Shooter reduction pipeline (version 3.2.0) is available at and the HiPERCAM pipeline at The lightcurve-fitting method is available at The codes used to generate the plots presented in this paper are available from the corresponding author upon reasonable request.


  1. 1.

    Maxted, P. F. L. & Marsh, T. R. The fraction of double degenerates among DA white dwarfs. Mon. Not. R. Astron. Soc. 307, 122–132 (1999).

    ADS  Google Scholar 

  2. 2.

    Nelemans, G., Yungelson, L. R. & PortegiesZwart, S. F. The gravitational wave signal from the Galactic disk population of binaries containing two compact objects. Astron. Astrophys. 375, 890–898 (2001).

    ADS  Google Scholar 

  3. 3.

    Tutukov, A. V. & Yungelson, L. R. On the influence of emission of gravitational waves on the evolution of low-mass close binary stars. Acta Astron. 29, 665–680 (1979).

    ADS  Google Scholar 

  4. 4.

    Webbink, R. F. Double white dwarfs as progenitors of R Coronae Borealis stars and type I supernovae. Astrophys. J. 277, 355–360 (1984).

    ADS  Google Scholar 

  5. 5.

    Paczyński, B. Gravitational waves and the evolution of close binaries. Acta Astron. 17, 287 (1967).

    ADS  Google Scholar 

  6. 6.

    Iben, Icko Jr., Tutukov, A. V. & Yungelson, L. R. On the origin of hydrogen-deficient supergiants and their relation to R Coronae Borealis stars and non-DA white dwarfs. Astrophys. J. 456, 750 (1996).

    ADS  Google Scholar 

  7. 7.

    Han, Z., Podsiadlowski, P., Maxted, P. F. L. & Marsh, T. R. The origin of subdwarf B stars— II. Mon. Not. R. Astron. Soc. 341, 669–691 (2003).

    ADS  Google Scholar 

  8. 8.

    Nelemans, G. The Galactic gravitational wave foreground. Class. Quant. Gravity 26, 094030 (2009).

    ADS  MATH  Google Scholar 

  9. 9.

    Marsh, T. R. Double white dwarfs and LISA. Class. Quant. Gravity 28, 094019 (2011).

    ADS  MATH  Google Scholar 

  10. 10.

    Nomoto, K. & Kondo, Y. Conditions for accretion-induced collapse of white dwarfs. Astrophys. J. Lett. 367, L19–L22 (1991).

    ADS  Google Scholar 

  11. 11.

    Parsons, S. G. et al. Testing the white dwarf mass-radius relationship with eclipsing binaries. Mon. Not. R. Astron. Soc. 470, 4473–4492 (2017).

    ADS  Google Scholar 

  12. 12.

    Fontaine, G. & Brassard, P. The pulsating white dwarf stars. Publ. Astron. Soc. Pacif. 120, 1043 (2008).

    ADS  Google Scholar 

  13. 13.

    Winget, D. E. & Kepler, S. O. Pulsating white dwarf stars and precision asteroseismology. Annu. Rev. Astron. Astrophys. 46, 157–199 (2008).

    ADS  Google Scholar 

  14. 14.

    Althaus, L. G., Córsico, A. H., Isern, J. & García-Berro, E. Evolutionary and pulsational properties of white dwarf stars. Astron. Astrophys. Rev. 18, 471–566 (2010).

    ADS  Google Scholar 

  15. 15.

    Charpinet, S., Brassard, P., Giammichele, N. & Fontaine, G. Improved seismic model of the pulsating DB white dwarf KIC 08626021 corrected from the effects of neutrino cooling. Astron. Astrophys. 628, L2 (2019).

    ADS  Google Scholar 

  16. 16.

    Clemens, J. C., O’Brien, P. C., Dunlap, B. H. & Hermes, J. J. Seismology of an ensemble of ZZ Ceti stars. In 20th Eur. White Dwarf Workshop—Astronomical Society of the Pacific Conference Series Vol. 509 (eds Tremblay, P. E., Gaensicke, B. & Marsh, T.) 255 (ASP, 2017).

  17. 17.

    Zenati, Y., Toonen, S. & Perets, H. B. Formation and evolution of hybrid He-CO white dwarfs and their properties. Mon. Not. R. Astron. Soc. 482, 1135–1142 (2019).

    ADS  Google Scholar 

  18. 18.

    Córsico, A. H., Althaus, L. G., MillerBertolami, M. M. & Kepler, S. O. Pulsating white dwarfs: new insights. Astron. Astrophys. Rev. 27, 7 (2019).

    ADS  Google Scholar 

  19. 19.

    Córsico, A. H. & Althaus, L. G. Pulsating low-mass white dwarfs in the frame of new evolutionary sequences. I. Adiabatic properties. Astron. Astrophys. 569, A106 (2014).

    ADS  Google Scholar 

  20. 20.

    Bell, K. J. et al. Pruning the ELM survey: characterizing candidate low-mass white dwarfs through photometric variability. Astrophys. J. 835, 180 (2017).

    ADS  Google Scholar 

  21. 21.

    Pyrzas, S. et al. Discovery of ZZ Cetis in detached white dwarf plus main-sequence binaries. Mon. Not. R. Astron. Soc. 447, 691–697 (2015).

    ADS  Google Scholar 

  22. 22.

    Hermes, J. J. et al. Insights into internal effects of common-envelope evolution using the extended Kepler mission. Mon. Not. R. Astron. Soc. 451, 1701–1712 (2015).

    ADS  Google Scholar 

  23. 23.

    Hallakoun, N. et al. SDSS J1152+0248: an eclipsing double white dwarf from the Kepler K2 campaign. Mon. Not. R. Astron. Soc. 458, 845–854 (2016).

    ADS  Google Scholar 

  24. 24.

    Vernet, J. et al. X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope. Astron. Astrophys. 536, A105 (2011).

    Google Scholar 

  25. 25.

    Dhillon, V. et al. First light with HiPERCAM on the GTC. In Ground-based and Airborne Instrumentation for Astronomy VII—Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series 107020L (SPIE, 2018).

  26. 26.

    Copperwheat, C. M. et al. Physical properties of IP Pegasi: an eclipsing dwarf nova with an unusually cool white dwarf. Mon. Not. R. Astron. Soc. 402, 1824–1840 (2010).

    ADS  Google Scholar 

  27. 27.

    Rasmussen, C. E. & Williams, C. K. I. Gaussian Processes for Machine Learning (MIT Press, 2006).

  28. 28.

    Koester, D. White dwarf spectra and atmosphere models. Mem. Soc. Astron. Ital. 81, 921–931 (2010).

    ADS  Google Scholar 

  29. 29.

    Scargle, J. D. Studies in astronomical time series analysis. II. Statistical aspects of spectral analysis of unevenly spaced data. Astrophys. J. 263, 835–853 (1982).

    ADS  Google Scholar 

  30. 30.

    Kilic, M. et al. A refined search for pulsations in white dwarf companions to millisecond pulsars. Mon. Not. R. Astron. Soc. 479, 1267–1272 (2018).

    ADS  Google Scholar 

  31. 31.

    Marsh, T. R., Dhillon, V. S. & Duck, S. R. Low-mass white dwarfs need friends—five new double-degenerate close binary stars. Mon. Not. R. Astron. Soc. 275, 828 (1995).

    ADS  Google Scholar 

  32. 32.

    Bours, M. C. P. et al. Precise parameters for both white dwarfs in the eclipsing binary CSS 41177. Mon. Not. R. Astron. Soc. 438, 3399–3408 (2014).

    ADS  Google Scholar 

  33. 33.

    Bours, M. C. P., Marsh, T. R., Gänsicke, B. T. & Parsons, S. G. HST+COS spectra of the double white dwarf CSS 41177 place the secondary inside the pulsational instability strip. Mon. Not. R. Astron. Soc. 448, 601–605 (2015).

    ADS  Google Scholar 

  34. 34.

    Istrate, A. G. et al. Models of low-mass helium white dwarfs including gravitational settling, thermal and chemical diffusion, and rotational mixing. Astron. Astrophys. 595, A35 (2016).

    Google Scholar 

  35. 35.

    PradaMoroni, P. G. & Straniero, O. Very low-mass white dwarfs with a C-O core. Astron. Astrophys. 507, 1575–1583 (2009).

    ADS  Google Scholar 

  36. 36.

    Han, Z., Tout, C. A. & Eggleton, P. P. Low- and intermediate-mass close binary evolution and the initial-final mass relation. Mon. Not. R. Astron. Soc 319, 215–222 (2000).

    ADS  Google Scholar 

  37. 37.

    Tremblay, P. E., Kalirai, J. S., Soderblom, D. R., Cignoni, M. & Cummings, J. White dwarf cosmochronology in the solar neighborhood. Astrophys. J. 791, 92 (2014).

    ADS  Google Scholar 

  38. 38.

    Press, W. H., Teukolsky, A. A., Vetterling, W. T. & Flannery, B. P. Numerical Recipes. The Art of Scientific Computing 3rd edn (Cambridge Univ. Press, 2007).

  39. 39.

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

    ADS  Google Scholar 

  40. 40.

    Holberg, J. B. & Bergeron, P. Calibration of synthetic photometry using DA white dwarfs. Astron. J. 132, 1221–1233 (2006).

    ADS  Google Scholar 

  41. 41.

    Tremblay, P. E., Bergeron, P. & Gianninas, A. An improved spectroscopic analysis of DA white dwarfs from the Sloan Digital Sky Survey data release 4. Astrophys. J. 730, 128 (2011).

    ADS  Google Scholar 

  42. 42.

    Claret, A. Non-linear limb-darkening law for LTE models. VizieR 336, 31081 (2000).

    Google Scholar 

  43. 43.

    Gianninas, A., Strickland, B. D., Kilic, M. & Bergeron, P. Limb-darkening coefficients for eclipsing white dwarfs. Astrophys. J. 766, 3 (2013).

    ADS  Google Scholar 

  44. 44.

    Foreman-Mackey, D., Agol, E., Ambikasaran, S. & Angus, R. Fast and scalable Gaussian process modeling with applications to astronomical time series. Astron. J. 154, 220 (2017).

    ADS  Google Scholar 

  45. 45.

    Fontaine, G., Brassard, P. & Bergeron, P. The potential of white dwarf cosmochronology. Publ. Astron. Soc. Pacif. 113, 409–435 (2001).

    ADS  Google Scholar 

  46. 46.

    GaiaCollaboration et al. Gaia Data Release 2. Summary of the contents and survey properties. Astron. Astrophys. 616, A1 (2018).

    Google Scholar 

  47. 47.

    Schlafly, E. F. & Finkbeiner, D. P. Measuring reddening with Sloan Digital Sky Survey stellar spectra and recalibrating SFD. Astrophys. J. 737, 103 (2011).

    ADS  Google Scholar 

  48. 48.

    Lenz, P. & Breger, M. Period04 user guide. Comm. Asteroseismol. 146, 53–136 (2005).

    ADS  Google Scholar 

  49. 49.

    Hermes, J. J. et al. White dwarf rotation as a function of mass and a dichotomy of mode line widths: Kepler observations of 27 pulsating DA white dwarfs through K2 campaign 8. Astrophys. J. Suppl. 232, 23 (2017).

    ADS  Google Scholar 

  50. 50.

    Bailer-Jones, C. A. L., Rybizki, J., Fouesneau, M., Mantelet, G. & Andrae, R. Estimating distance from parallaxes. IV. Distances to 1.33 billion stars in Gaia data release 2. Astron. J. 156, 58 (2018).

    ADS  Google Scholar 

  51. 51.

    Panei, J. A., Althaus, L. G., Chen, X. & Han, Z. Full evolution of low-mass white dwarfs with helium and oxygen cores. Mon. Not. R. Astron. Soc. 382, 779–792 (2007).

    ADS  Google Scholar 

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S.G.P. acknowledges the support of a Science and Technology Facilities Council Ernest Rutherford Fellowship. HiPERCAM and V.S.D. are funded by the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) under ERC-2013-ADG grant agreement number 340040 (HiPERCAM). Partial support for this work was provided by NASA K2 Cycle 6 Grant 80NSSC19K0162. A.G.I. acknowledges support from the Netherlands Organisation for Scientific Research. This work is based on observations made with the Gran Telescopio Canarias (programme ID GTC59-18B), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma, and also based on observations made with the European Southern Observatory telescopes at the La Silla Paranal Observatory under programme ID 097.D-0786.

Author information




All authors contributed to the work presented in this paper. S.G.P. reduced all the spectroscopic and photometric data and carried out the SED fitting. S.G.P. and V.S.D. performed the Gran Telescopio Canarias observations. A.J.B. performed the radial-velocity and lightcurve fitting. S.P.L. wrote the Python code that implemented the Gaussian processes in the lightcurve fitting. V.S.D., S.P.L., T.R.M., S.G.P., E.B., M.J.D., M.J.G. and D.I.S. all contributed to the development and support of HiPERCAM. J.J.H. analysed the pulsations in the HiPERCAM lightcurves. A.G.I. investigated the internal structure of the white dwarfs and the evolution of the binary. All authors reviewed the manuscript.

Corresponding author

Correspondence to Steven G. Parsons.

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The authors declare no competing interests.

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Peer review information Nature Astronomy thanks Alejandro Córsico, Ingrid Pelisoli and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Parsons, S.G., Brown, A.J., Littlefair, S.P. et al. A pulsating white dwarf in an eclipsing binary. Nat Astron 4, 690–696 (2020).

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