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.

Stabilization of the disk around β Pictoris by extremely carbon-rich gas


The edge-on disk surrounding the nearby young star β Pictoris is the archetype of ‘debris disks’, which are composed of dust and gas produced by collisions between—and evaporation of—planetesimals, analogues of Solar System comets and asteroids. These disks may provide insight into the formation and early evolution of terrestrial planets. Previous work on β Pic concluded that the disk gas has roughly solar abundances of elements1, but this poses a problem because such gas should rapidly be blown away from the star, contrary to observations showing a stable gas disk in keplerian rotation1,2. Here we report the detection of singly and doubly ionized carbon (C ii, C iii) and neutral atomic oxygen (O i) gas in the β Pic disk. Carbon is extremely overabundant relative to every other measured element. This appears to solve the problem of the stable gas disk, because the carbon overabundance should keep the gas disk in keplerian rotation3. The overabundance may indicate that the gas is produced from material more carbon-rich than expected of Solar System analogues.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Circumstellar absorption lines in far-ultraviolet spectra of β Pic.
Figure 2: Bulk composition of β Pic stable circumstellar gas.


  1. Lagrange, A.-M. et al. The β Pictoris circumstellar disk. XXIV. Clues to the origin of the stable gas. Astron. Astrophys. 330, 1091–1108 (1998)

    ADS  CAS  Google Scholar 

  2. Brandeker, A., Liseau, R., Olofsson, G. & Fridlund, M. The spatial structure of the β Pictoris gas disk. Astron. Astrophys. 413, 681–691 (2004)

    ADS  CAS  Article  Google Scholar 

  3. Fernández, R., Brandeker, A. & Wu, Y. Braking the gas in the β Pictoris disk. Astrophys. J. (in the press); preprint at (2006)

  4. Holweger, H., Hempel, M., van Thiel, T. & Kaufer, A. The surface composition of β Pictoris. Astron. Astrophys. 320, L49–L52 (1997)

    ADS  CAS  Google Scholar 

  5. Zuckerman, B., Song, I., Bessell, M. S. & Webb, R. A. The β Pictoris moving group. Astrophys. J. 562, L87–L90 (2001)

    ADS  Article  Google Scholar 

  6. Slettebak, A. Some interesting bright southern stars of early type. Astrophys. J. 197, 137–138 (1975)

    ADS  CAS  Article  Google Scholar 

  7. Beust, H., Vidal-Madjar, A., Ferlet, R. & Lagrange-Henri, A. M. The β Pictoris circumstellar disk. X—Numerical simulations of infalling evaporating bodies. Astron. Astrophys. 236, 202–216 (1990)

    ADS  CAS  Google Scholar 

  8. Olofsson, G., Liseau, R. & Brandeker, A. Widespread atomic gas emission reveals the rotation of the β Pictoris disk. Astrophys. J. 563, L77–L80 (2001)

    ADS  CAS  Article  Google Scholar 

  9. Roberge, A. et al. High-resolution Hubble Space Telescope STIS spectra of C I and CO in the β Pictoris circumstellar disk. Astrophys. J. 538, 904–910 (2000)

    ADS  CAS  Article  Google Scholar 

  10. Lodders, K. Solar System abundances and condensation temperatures of the elements. Astrophys. J. 591, 1220–1247 (2003)

    ADS  CAS  Article  Google Scholar 

  11. Jessberger, E. K., Christoforidis, A. & Kissel, J. Aspects of the major element composition of Halley's dust. Nature 332, 691–695 (1988)

    ADS  CAS  Article  Google Scholar 

  12. Freudling, W., Lagrange, A.-M., Vidal-Madjar, A., Ferlet, R. & Forveille, T. Gas around β Pictoris: An upper limit on the H I content. Astron. Astrophys. 301, 231–235 (1995)

    ADS  CAS  Google Scholar 

  13. Vidal-Madjar, A. et al. HST-GHRS observations of β Pictoris: Additional evidence for infalling comets. Astron. Astrophys. 290, 245–258 (1994)

    ADS  CAS  Google Scholar 

  14. Crawford, I. A., Spyromilio, J., Barlow, M. J., Diego, F. & Lagrange, A.-M. Ultra-high-resolution observations of Ca K line variations in the β Pictoris disc. Mon. Not. R. Astron. Soc. 266, L65–L68 (1994)

    ADS  CAS  Article  Google Scholar 

  15. A'Hearn, M. F. et al. Deep Impact: excavating comet Tempel 1. Science 310, 258–264 (2005)

    ADS  CAS  Article  Google Scholar 

  16. Chen, C. H. & Jura, M. The low-velocity wind from the circumstellar matter around the B9V star σ Herculis. Astrophys. J. 582, 443–448 (2003)

    ADS  CAS  Article  Google Scholar 

  17. Deleuil, M. et al. Is β Pictoris an active star? Astrophys. J. 557, L67–L70 (2001)

    ADS  CAS  Article  Google Scholar 

  18. Bouret, J.-C. et al. A chromospheric scenario for the activity of β Pictoris, as revealed by FUSE. Astron. Astrophys. 390, 1049–1061 (2002)

    ADS  Article  Google Scholar 

Download references


We thank D. Lindler for recalibrating the archival STIS spectra used in this paper. The work at JHU was supported by NASA.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Aki Roberge.

Ethics declarations

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Notes

This document contains details of the observations and analysis. It includes one Supplementary Figure showing contours of χ2 from analysis of the OI absorption line. The document has three Supplementary Tables, 1) an observation log, 2) a complete inventory of all species in the β Pic stable gas, and 3) a table with calculated elemental ionization fractions. (PDF 71 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Roberge, A., Feldman, P., Weinberger, A. et al. Stabilization of the disk around β Pictoris by extremely carbon-rich gas. Nature 441, 724–726 (2006).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


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