Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Discovery of a brown dwarf in the Pleiades star cluster


BROWN dwarfs are cool star-like objects that have insufficient mass to maintain stable nuclear fusion in their interiors. Although brown dwarfs are not stars, they are expected to form in the same way, and their frequency of occurrence should reflect the trends seen in the birthrates of low-mass stars. But finding brown dwarfs has proved to be difficult, because of their low intrinsic luminosity. The nearby Pleiades star cluster is widely recognized as a likely host for detectable brown dwarfs because of its young age — the still-contracting brown dwarfs should radiate a large fraction of their gravitational energy at near-infrared wavelengths. Here we report the discovery of a brown dwarf near the centre of the Pleiades. The luminosity and temperature of this object are so low that its mass must be less than 0.08 solar masses, the accepted lower limit on the mass of a true star1–3. The detection of only one brown dwarf within our survey area is consistent with a smooth extrapolation of the stellar mass function of the Pleiades4, suggesting that brown dwarfs, although probably quite numerous in the Galactic disk, are unlikely to comprise more than ˜1% of its mass.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others


  1. Burrows, A., Hubbard, W. B., Saumon, D. & Lunine, J. I. Astrophys. J. 406, 158–171 (1993).

    Article  ADS  Google Scholar 

  2. D'Antona, F. & Mazzitelli, I. Astrophys. J. Suppl. 90, 467–500 (1994).

    Article  ADS  CAS  Google Scholar 

  3. Nelson, L. A., Rappaport, S. & Chiang, E. Astrophys. J. 413, 364–367 (1993).

    Article  ADS  CAS  Google Scholar 

  4. Laughlin, G. & Bodenheimer, P. Astrophys. J. 403, 303–314 (1993).

    Article  ADS  Google Scholar 

  5. Kirkpatrick, J. D., Henry, T. J. & Simons, D. A. Astr. J. 109, 797–807 (1995).

    Article  ADS  Google Scholar 

  6. Kirkpatrick, J. D. & McCarthy, D. W. Astr. J. 107, 333–349 (1994).

    Article  ADS  CAS  Google Scholar 

  7. Henry, T. J. & McCarthy, D. W. Astr. J. 106, 773–789 (1993).

    Article  ADS  Google Scholar 

  8. Hambly, N. C., Hawkins, M. R. S. & Jameson, R. F. Astr. Astrophys. Suppl. 100, 607–640 (1993).

    ADS  Google Scholar 

  9. Stauffer, J. R., Hamilton, D. & Probst, R. G. Astr. J. 108, 155–159 (1994).

    Article  ADS  Google Scholar 

  10. Rebolo, R., Martín, E. L. & Magazzù, A. Astrophys. J. 389, L83–L86 (1992).

    Article  ADS  CAS  Google Scholar 

  11. Magazzù, A., Martín, E. L. & Rebolo, R. Astrophys. J. 404, L17–L20 (1993).

    Article  ADS  Google Scholar 

  12. Martín, E. L., Rebolo, R. & Magazzú, A. Astrophys. J. 436, 262–269 (1994).

    Article  ADS  Google Scholar 

  13. Marcy, G. W., Basri, G. & Graham, J. R. Astrophys. J. 428, L57–L60 (1994).

    Article  ADS  CAS  Google Scholar 

  14. Basri, G., Marcy, G. & Graham, J. R. Bull. Am. astr. Soc. (in the press).

  15. Jameson, R. F. & Skillen, W. J. Mon. Not. R. astr. Soc. 239, 247–253 (1989).

    Article  ADS  Google Scholar 

  16. Jones, B. F. Astr. J. 86, 290–297 (1981).

    Article  ADS  Google Scholar 

  17. Stauffer, J. R., Liebert, J. & Giampapa, M. Astr. J. 109, 298–311 (1995).

    Article  ADS  Google Scholar 

  18. Stauffer, J. R. et al. Astr. J. 108, 160–174 (1994).

    Article  ADS  Google Scholar 

  19. Hodgkin, S. T., Jameson, R. F. & Steele, I. A. Mon. Not. R. astr. Soc. 274, 869–883 (1995).

    Article  ADS  CAS  Google Scholar 

  20. Martín, E. L. thesis, Univ. La Laguna (1993).

  21. Marcy, G. & Benitz, K. Astrophys. J. 344, 441–453 (1989).

    Article  ADS  Google Scholar 

  22. Rosvick, J. M., Mermilliod, J. C. & Mayor, M. Astr. Astrophys. 255, 130–138 (1992).

    ADS  Google Scholar 

  23. Kirkpatrick, J. D., McGraw, J. T., Hess, T. R., Liebert, J. & McCarthy, D. W. Astrophys. J. Suppl. 94, 749–788 (1994).

    Article  ADS  Google Scholar 

  24. Monet, D. G. et al. Astr. J. 103, 638–665 (1992).

    Article  ADS  Google Scholar 

  25. Kirkpatrick, J. D. et al. Astrophys. J. 402, 643–654 (1993).

    Article  ADS  Google Scholar 

  26. Brett, J. M. Astr. Astrophys. 295, 736–754 (1995).

    ADS  CAS  Google Scholar 

  27. Tinney, C. G., Mould, J. R. & Reig, N. Astr. J. 105, 1045–1059 (1993).

    Article  ADS  CAS  Google Scholar 

  28. Bessell, M. S. & Stringfellow, G. S. A. Rev. Astr. Astrophys. 31, 433–471 (1993).

    Article  ADS  CAS  Google Scholar 

  29. Hamilton, D. & Stauffer, J. R. Astr. J. 105, 1855–1859 (1993).

    Article  ADS  CAS  Google Scholar 

  30. Prosser, C. F., Stauffer, J. R. & Kraft, R. P. Astr. J. 101, 1361–1376 (1991).

    Article  ADS  CAS  Google Scholar 

  31. Baraffe, I., Chabrier, G., Allard, F. & Hauschildt, P. H. Astrophys. J. 446, L35–L38 (1995).

    Article  ADS  CAS  Google Scholar 

  32. Pavlenko, Ya. V., Rebolo, R., Martin, E. L. & García López, R. J. Astr. Astrophys. (in the press).

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and permissions

About this article

Cite this article

Rebolo, R., Osorio, M. & Martín, E. Discovery of a brown dwarf in the Pleiades star cluster. Nature 377, 129–131 (1995).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing