Abstract

A speckle interferometer for use at the Cassegrain focus of large telescopes has been constructed and used to observe binary star systems on the 2.5 m Isaac Newton telescope in England. The instrument has a four-stage, magnetically focused EMI image intensifier with a maximum light gain in excess of 106, good resolution, and low background noise. The final images are recorded on 16mm cine film. Both analog optical and digital analyses have been carried out. The digital analysis enables the transfer function of the speckle method to be found and divided into the image power spectrum. Examples are given of experimental results. Binary star separations have been measured for stars as close as 0.1 arc sec and as faint as magnitude 6.

© 1976 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. A. Labeyrie, Astron. Astrophys. 6, 85 (1970).
  2. A. Labeyrie, in Progress in Optics (North-Holland, Amsterdam, 1976), Vol. XIV.
  3. J. C. Dainty, in Topics in Applied Physics (Springer-Verlag, Berlin, 1975), Vol. 9.
  4. D. Korff, J. Opt. Soc. Am. 63, 971 (1973).
    [CrossRef]
  5. K. T. Knox and B. J. Thompson, Astrophys. J. 193, L45 (1974).
    [CrossRef]
  6. P. Nisenson and D. C. Ehn, J. Opt. Soc. Am. 65, 1196 (1975).
  7. J. W. Sherman, OSA Topical Meeting on Image Processing, Pacific Grove, Calif. (Feb. 1976) paper ThB 11.
  8. C. R. Lynds, S. P. Worden, and J. W. Harvey, Astrophys. J. (to be published).
  9. C. Roddier and F. Roddier, J. Opt. Soc. Am. 65, 664 (1975).
    [CrossRef]
  10. D. Bonneau, M. Josse, and A. Labeyrie, in Image Processing Techniques in Astronomy (D. Reidel, Dordrecht, Holland, 1975), p. 403.
    [CrossRef]
  11. A. M. Schneidermann, P. F. Kellen, and M. G. Miller, J. Opt. Soc. Am. 65, 1287 (1975).
    [CrossRef]

1975 (3)

1974 (1)

K. T. Knox and B. J. Thompson, Astrophys. J. 193, L45 (1974).
[CrossRef]

1973 (1)

1970 (1)

A. Labeyrie, Astron. Astrophys. 6, 85 (1970).

Bonneau, D.

D. Bonneau, M. Josse, and A. Labeyrie, in Image Processing Techniques in Astronomy (D. Reidel, Dordrecht, Holland, 1975), p. 403.
[CrossRef]

Dainty, J. C.

J. C. Dainty, in Topics in Applied Physics (Springer-Verlag, Berlin, 1975), Vol. 9.

Ehn, D. C.

P. Nisenson and D. C. Ehn, J. Opt. Soc. Am. 65, 1196 (1975).

Harvey, J. W.

C. R. Lynds, S. P. Worden, and J. W. Harvey, Astrophys. J. (to be published).

Josse, M.

D. Bonneau, M. Josse, and A. Labeyrie, in Image Processing Techniques in Astronomy (D. Reidel, Dordrecht, Holland, 1975), p. 403.
[CrossRef]

Kellen, P. F.

Knox, K. T.

K. T. Knox and B. J. Thompson, Astrophys. J. 193, L45 (1974).
[CrossRef]

Korff, D.

Labeyrie, A.

A. Labeyrie, Astron. Astrophys. 6, 85 (1970).

A. Labeyrie, in Progress in Optics (North-Holland, Amsterdam, 1976), Vol. XIV.

D. Bonneau, M. Josse, and A. Labeyrie, in Image Processing Techniques in Astronomy (D. Reidel, Dordrecht, Holland, 1975), p. 403.
[CrossRef]

Lynds, C. R.

C. R. Lynds, S. P. Worden, and J. W. Harvey, Astrophys. J. (to be published).

Miller, M. G.

Nisenson, P.

P. Nisenson and D. C. Ehn, J. Opt. Soc. Am. 65, 1196 (1975).

Roddier, C.

Roddier, F.

Schneidermann, A. M.

Sherman, J. W.

J. W. Sherman, OSA Topical Meeting on Image Processing, Pacific Grove, Calif. (Feb. 1976) paper ThB 11.

Thompson, B. J.

K. T. Knox and B. J. Thompson, Astrophys. J. 193, L45 (1974).
[CrossRef]

Worden, S. P.

C. R. Lynds, S. P. Worden, and J. W. Harvey, Astrophys. J. (to be published).

Astron. Astrophys. (1)

A. Labeyrie, Astron. Astrophys. 6, 85 (1970).

Astrophys. J. (1)

K. T. Knox and B. J. Thompson, Astrophys. J. 193, L45 (1974).
[CrossRef]

J. Opt. Soc. Am. (4)

Other (5)

A. Labeyrie, in Progress in Optics (North-Holland, Amsterdam, 1976), Vol. XIV.

J. C. Dainty, in Topics in Applied Physics (Springer-Verlag, Berlin, 1975), Vol. 9.

J. W. Sherman, OSA Topical Meeting on Image Processing, Pacific Grove, Calif. (Feb. 1976) paper ThB 11.

C. R. Lynds, S. P. Worden, and J. W. Harvey, Astrophys. J. (to be published).

D. Bonneau, M. Josse, and A. Labeyrie, in Image Processing Techniques in Astronomy (D. Reidel, Dordrecht, Holland, 1975), p. 403.
[CrossRef]

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (8)

FIG. 1
FIG. 1

Short-exposure (0.008 s) image of the unresolvable star Vega recorded using the speckle interferometer on the 2.5 m Isaac Newton telescope of the Royal Greenwich Observatory.

FIG. 2
FIG. 2

Schematic diagram of the speckle interferometer.

FIG. 3
FIG. 3

Schematic diagram showing the analogue technique of data analysis.

FIG. 4
FIG. 4

Fringes obtained by using the analog method to add the squared moduli of the Fourier transforms of approximately 500 images of the binary system β Delphini. The fringe spacing corresponds to an angular separation of the stars of 0.58 arc sec.

FIG. 5
FIG. 5

Fringes obtained by using the analog method to add the squared moduli of the Fourier transforms of approximately 500 images of the binary system δ Equi. The fringe spacing corresponds to an angular separation of 0.15 arc sec.

FIG. 6
FIG. 6

(a) Result of applying the digital data processing technique to images of the binary system β Delphini. 32 images have been scanned and digitized using a PDS microdensitometer and the squared moduli of their Fourier transforms calculated and summed in a computer for display by a Calcomp Plotter. (b) Result of normalizing the data shown in (a) by dividing by the transfer function derived from observations of a nearby unresolvable star.

FIG. 7
FIG. 7

Typical normalised transfer function obtained from short-exposure (0.008 s) observations of the unresolvable star Vega.

FIG. 8
FIG. 8

(a) Result of applying the digital data processing technique to 32 images of the binary system β Cephei. (b) Result of normalizing the data of (a) by the transfer function derived from observations of a nearby unresolvable star. Fringes are now clearly visible, their spacing corresponds to an angular separation of 0.29 arc sec.

Equations (8)

Equations on this page are rendered with MathJax. Learn more.

I ( x , y ) = O ( x , y ) P ( x , y ) ,
i ( u , v ) = o ( u , v ) T ( u , v ) ,
W ( u , v ) i ( u , v ) 2 = o ( u , v ) 2 T ( u , v ) 2 .
T ( u , v ) 2 T ( u , v ) 2 + k T D ( u , v ) ,
k ( d 0 / D ) 2 ,
C ( x , y ) = I ( x , y ) * I ( x , y ) = { O ( x , y ) * O ( x , y ) } { P ( x , y ) * P ( x , y ) } ,
M tot = A 3 / p 2 .
λ ¯ / δ λ D / d 0 ,