Your PDF has successfully downloaded.

You may be interested in finding more content on these topics:


You are not currently logged in.

Access JSTOR through your library or other institution:


Log in through your institution.

Journal Article

Speckle Noise and the Detection of Faint Companions

René Racine, Gordon A. H. Walker, Daniel Nadeau, René Doyon and Christian Marois
Publications of the Astronomical Society of the Pacific
Vol. 111, No. 759 (May 1999), pp. 587-594
DOI: 10.1086/316367
Stable URL:
Page Count: 8
Were these topics helpful?
See something inaccurate? Let us know!

Select the topics that are inaccurate.

  • Download PDF
  • Add to My Lists
  • Cite this Item
We're having trouble loading this content. Download PDF instead.


ABSTRACT Speckles dominate shot noise within the halo of adaptively corrected bright star images and, consequently, impose severe limits on ground‐based attempts to directly detect planets around nearby stars. The effect is orders of magnitude greater than conventional photon noise. It depends on the dwell time of the speckle pattern, the brightness of the star, and the fraction \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $( 1-S) $ \end{document} of residual light in the halo (S being the Strehl ratio of the image). These predictions agree well with limits found using the Canada‐France‐Hawaii Telescope adaptive optics bonnette. The limiting brightness for detection is proportional to \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $( 1-S) / S$ \end{document} , emphasizing the need for large Strehl ratios. Strategies to reduce speckle noise are proposed; the encouraging results of a test are presented.

Notes and References

This item contains 25 references.

  • ['Angel, J. R.\nP. 1994, Nature, 368, 203']
  • ['———.\n1995, Ap&SS, 223, 117']
  • ["Ftaclas, C.\n1994, in 15th NSO/Sacramento Peak Workshop, IR Tools for Solar\nAstrophysics: What's Next?, ed. J. R. Kuhn & M. J. Penn (Singapore:\nWorld Scientific), 181"]
  • ['Gatewood, G.\n1996, BAAS, 28, 885']
  • ['Henry, T. J.,\n& McCarthy, D. W. 1990, ApJ, 350, 334']
  • ['Kuhn, J. R.,\n& Loranz, D. 1991, PASP, 103, 1097']
  • ['Langlois, M.,\nSandler, D., Ryan, P., & McCarthy, D. 1998, Proc. SPIE, 3353,\n189']
  • ['Marcy, G.,\n& Butler, P. 1996, ApJ, 464, L147']
  • ['Mayor, M.,\n& Queloz, D. 1995, Nature, 378, 355']
  • ['Moffat, A.\nF. J. 1969, A&A, 3, 455']
  • ['Nadeau, D.,\nMurphy, D. C., Doyon, R., & Rowlands, N. 1994, PASP, 106,\n909']
  • ['Nakajima, T.\n1994, ApJ, 425, 348']
  • ['Olivier, S.\nS., Gavel, D. T., & Brase, J. M. 1995, Ap&SS, 223 181']
  • ['Rigaut, F.,\net al. 1998, PASP, 110, 52']
  • ['Roddier, F.\n1981, Prog. Opt., 19, 281']
  • ['———.\n1995, Ap&SS, 223, 109']
  • ['———.\n1998, PASP, 110, 837']
  • ['Roddier, F.,\nGilli, J. M., & Lund, G. 1982, J. Opt. (Paris), 13, 263']
  • ['Roddier, C.,\n& Roddier, F. 1995, Ap&SS, 223, 183']
  • ['Rosenthal,\nE. D., Gurwell, M. A., & Ho, P. T. P. 1996, Nature, 384, 243']
  • ['Ryan, P. T.,\nFugate, R. Q., Langlois, M., & Sandler, D. G. 1998, Proc. SPIE, 3353,\n107']
  • ['Stadhl, S.,\n& Sandler, D. G. 1995, ApJ, 454, L153']
  • ['Tonry, J.,\n& Schneider, D. P. 1988, AJ, 96, 807']
  • ['Tyson, J. A.\n1986, J. Opt. Soc. Am., A3, 2131']
  • ['Walker, G.\nA. H., Walker, A. R., Irwin, A. W., Larson, A. M., Yang, S. L. S., &\nRichardson, D. C. 1995, Icarus, 116, 359']