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Mid-infrared images of β Pictoris and the possible role of planetesimal collisions in the central disk


When viewed in optical starlight scattered by dust, the nearly edge-on debris disk surrounding the A5V star β Pictoris (distance 19.3 pc; ref. 1) extends farther than 1,450 au from the star2. Its large-scale complexity has been well characterized, but the detailed structure of the disk's central 200-au region has remained elusive. This region is of special interest, because planets may have formed there during the star's 10–20-million-year lifetime3,4, perhaps resulting in both the observed tilt of 4.6 degrees relative to the large-scale main disk5,6 and the partial clearing of the innermost dust7,8,9. A peculiarity of the central disk (also possibly related to the presence of planets) is the asymmetry in the brightness of the ‘wings’9,10, in which the southwestern wing is brighter and more extended at 12 µm than the northeastern wing. Here we present thermal infrared images of the central disk that imply that the brightness asymmetry results from the presence of a bright clump composed of particles that may differ in size from dust elsewhere in the disk. We suggest that this clump results from the collisional grinding of resonantly trapped planetesimals or the cataclysmic break-up of a planetesimal.

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Figure 1: β Pic mid-infrared images.
Figure 2: SW flux divided by NE flux versus distance from star.
Figure 3: The residual emission.
Figure 4: Disk spectral energy distributions.
Figure 5: Model distributions for the NE side of disk.


  1. Crifo, F., Vidal-Madjar, A., Lallement, R., Ferlet, R. & Gerbaldi, M. β Pictoris revisited by Hipparcos. Star properties. Astron. Astrophys. 320, L29–L32 (1997)

    ADS  Google Scholar 

  2. Larwood, J. D. & Kalas, P. G. Close stellar encounters with planetesimal disks: the dynamics of asymmetry in the β Pictoris system. Mon. Not. R. Astron. Soc. 323, 402–416 (2001)

    ADS  Article  Google Scholar 

  3. Barrado y Navascués, D., Stauffer, J. R., Song, I. & Caillault, J.-P. The age of Beta Pictoris. Astrophys. J. 520, L123–L126 (1999)

    ADS  Article  Google Scholar 

  4. 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 

  5. Heap, S. et al. Space telescope imaging spectrograph coronagraphic observations of β Pictoris. Astrophys. J. 539, 435–444 (2000)

    ADS  Article  Google Scholar 

  6. Mouillet, D., Larwood, J. D., Papaloizou, J. C. B. & Lagrange, A. M. A planet on an inclined orbit as an explanation of the warp in the β Pictoris disc. Mon. Not. R. Astron. Soc. 292, 896–904 (1997)

    ADS  Article  Google Scholar 

  7. Telesco, C. M., Becklin, E. E., Wolstencroft, R. D. & Decher, R. Resolution of the circumstellar disk of β Pictoris at 10 and 20 µm. Nature 335, 51–53 (1988)

    ADS  Article  Google Scholar 

  8. Backman, D. E., Gillett, F. C. & Witteborn, F. C. Infrared observations and thermal models of the β Pictoris dust disk. Astrophys. J. 385, 670–679 (1992)

    ADS  Article  Google Scholar 

  9. Lagage, P. O. & Pantin, E. Dust depletion in the inner disk of Beta Pictoris as a possible indicator of planets. Nature 369, 628–630 (1994)

    ADS  Article  Google Scholar 

  10. Pantin, E., Lagage, P. O. & Artymowicz, P. Mid-infrared images and models of the β Pictoris dust disk. Astron. Astrophys. 327, 1123–1136 (1997)

    ADS  Google Scholar 

  11. Weinberger, A. J., Becklin, E. E. & Zuckerman, B. The first spatially resolved mid-infrared spectroscopy of β Pictoris. Astrophys. J. 584, L33–L37 (2003)

    ADS  CAS  Article  Google Scholar 

  12. Wahhaj, Z. et al. The inner rings of β Pictoris. Astrophys. J. 584, L27–L31 (2003)

    ADS  Article  Google Scholar 

  13. Okamoto, Y. K. et al. An extrasolar planetary system revealed by planetesimal belts in β Pictoris. Nature 431, 660–662 (2004)

    ADS  CAS  Article  Google Scholar 

  14. Li, A. & Greenberg, J. M. A comet dust model for the β Pictoris disk. Astron. Astrophys. 331, 291–313 (1998)

    ADS  Google Scholar 

  15. Ozernoy, L. M., Gorkavyi, N. N., Mather, J. C. & Taidakova, T. A. Signatures of exosolar planets in dust disks. Astrophys. J. 537, L147–L151 (2000)

    ADS  CAS  Article  Google Scholar 

  16. Sicardy, B., Beaugé, C., Ferraz-Mello, S., Lazzaro, D. & Roques, F. Capture of grains into resonances through Poynting-Robertson drag. Celest. Mech. Dyn. Astron. 57, 373–390 (1993)

    ADS  Article  Google Scholar 

  17. Dermott, S. F., Jayaraman, S., Xu, Y. L., Gustafson, B. & Liou, J. C. A circumsolar ring of asteroidal dust in resonant lock with the Earth. Nature 369, 719–723 (1994)

    ADS  Article  Google Scholar 

  18. Wyatt, M. C. et al. How observations of circumstellar disk asymmetries can reveal hidden planets: pericenter glow and its application to the HR4796 disk. Astrophys. J. 527, 918–944 (1999)

    ADS  Article  Google Scholar 

  19. Wyatt, M. C. Resonant trapping of planetesimals by planet migration: debris disk clumps and Vega's similarity to the Solar System. Astrophys. J. 598, 1321–1340 (2003)

    ADS  Article  Google Scholar 

  20. Lagrange-Henri, A. M., Vidal-Madjar, A. & Ferlet, R. The β Pictoris circumstellar disk. VI. Evidence for material falling on to the star. Astron. Astrophys. 190, 275–282 (1988)

    ADS  CAS  Google Scholar 

  21. Beust, H., Vidal-Madjar, A., Ferlat, R. & Lagrange-Henri, A. M. Cometary-like bodies in the protoplanetary disk around β Pictoris. Astrophys. Space Sci. 212, 147–157 (1994)

    ADS  CAS  Article  Google Scholar 

  22. Wyatt, M. C. & Dent, W. R. F. Collisional processes in extrasolar planetesimal discs—dust clumps in Fomalhaut's debris disc. Mon. Not. R. Astron. Soc. 334, 589–607 (2002)

    ADS  Article  Google Scholar 

  23. 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 

  24. Dominik, C. & Decin, G. Age dependence of the Vega phenomenon: theory. Astrophys. J. 598, 626–635 (2003)

    ADS  CAS  Article  Google Scholar 

  25. Hartmann, W. K. & Davis, D. R. Satellite-sized planetesimals and lunar origin. Icarus 24, 504–515 (1975)

    ADS  Article  Google Scholar 

  26. Dermott, S. F., Kehoe, T. J. J., Durda, D. D., Grogan, K. & Nesvorný, D. in Asteroids, Comets, and Meteors 2002 (ed. Warmbein, B.) ESA SP-500, 319–322 (Publications Division, Noordwijk, 2002)

    Google Scholar 

  27. Kenyon, S. J. & Bromley, B. C. Detecting the dusty debris of terrestrial planet formation. Astrophys. J. 602, L133–L136 (2004)

    ADS  Article  Google Scholar 

  28. Van Paradijs, J., Telesco, C. M., Kouveliotou, C. & Fishman, G. J. 10 micron detection of the hard x-ray transient GRO J0422+32: free-free emission from an x-ray-driven accretion disk wind? Astrophys. J. 429, L19–L23 (1994)

    ADS  Article  Google Scholar 

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We dedicate this paper to the memory of our colleague F. Gillett, infrared astronomy pioneer and co-discoverer of circumstellar debris disks. We thank K. Hanna, J. Julian and R. Piña for contributions to the success of T-ReCS; F. Varosi for assistance with data reduction; the Gemini Observatory staff in Chile, particularly M.-C. Hainaut-Rouelle, for technical assistance; and D. Simons of Gemini Observatory for support. This paper is based on observations (programme number GS-2003B-14) obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil) and CONICET (Argentina). This research was funded in part by an NSF grant to C.M.T.

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Correspondence to Charles M. Telesco.

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Telesco, C., Fisher, R., Wyatt, M. et al. Mid-infrared images of β Pictoris and the possible role of planetesimal collisions in the central disk. Nature 433, 133–136 (2005).

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