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The Effects of Filters and Colour on Stellar Occultations and Appropriate Deconvolution Procedures

Published online by Cambridge University Press:  30 March 2016

T. Krishnan
T. Krishnan*
Affiliation:
Astro Research Corporation, P.O. Box 4128, Santa Barbara, Calif. 93103, U.S.A.

Abstract

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The theory of the effect of bandwidth of lunar occultations is reviewed. It is recalled that effective beamshapes can be calculated for symmetrical bandpasses and that their widths are related to the absolute width in wavelength of the bandpasses. Restoration with the second differential of the theoretical Fresnel diffraction curves at the central wavelength, at the correct rates, yield source distributions as viewed by these beamshapes. It is shown that for asymmetric bandpasses, the real and odd parts taken about the centroids lead to equivalent even and odd beams. Assuming an approximate color temperature for the stars, the total system response can be evaluated and hence the even and odd parts. Restoration of the data should then be performed using the second differential of the Fresnel curve at the centroid wavelength to minimize the odd part, adjusting zeroes, rates, and centroids by inspection. The even part should then represent the even theoretical response convolved with the one-dimensional stellar distribution, provided the latter is circularly symmetrical.

The technique is applied to the occultation observation of λ-Aquarii by Nather et al. (1970) leading to closely similar results.

Type
III. Joint Discussions
Information
Highlights of Astronomy , Volume 2: Highlights of Astronomy. As presented at the XIVth General Assembly of the IAU, 1970 , 1971 , pp. 646 - 661
Copyright
Copyright © Reidel 1971

References

Berg, R. A.: 1960, ‘Stellar Angular Diameters from Lunar Occultations’, Ph.D. dissertation, Leander McCormick Observatory, University of Virginia.Google Scholar
Cohen, M. H.: 1969, Ann. Rev. Astron. Astrophys. 6 (Palo Alto, Calif.: Ann. Rev.), pp. ,13-38.Google Scholar
Cousins, A.W.J. and Guelke, R.: 1953, Monthly Notices Roy. Astron. Soc. 113, 776.Google Scholar
Eddington, A. S.: 1909, Monthly Notices Roy. Astron. Soc. 69, 178.Google Scholar
Evans, D. S.: 1951, Monthly Notices Roy. Astron. Soc. Ill, 64.Google Scholar
Evans, D. S.: 1955, Monthly Notices Roy Astron. Soc. 115, 466.Google Scholar
Evans, D. S.: 1957, Astron. J. 62, 83.Google Scholar
Evans, D. S., Heydenrych, J.C.R., and Van Wyck, D. N.: 1953, Monthly Notices Roy. Astron. Soc. 113,781.Google Scholar
Hoerner, S., Von.: 1964, Astrophys. J. 140, 65.Google Scholar
Johnson, H. L.: 1955, Ann. Astrophys. 18, 4, 292.Google Scholar
Krishnan, T.: 1970, J.Inst. Tellcom. Engrs. (India) 16, 61 and NASA Technical Note, NASA TND-5679.Google Scholar
Lang, K. R.: 1969, Astrophys. J. 158, 1189.Google Scholar
McNahon, P. A.: 1908, Monthly Notices Roy. Astron. Soc. 69, 126.Google Scholar
Nather, R. E., McCants, M. M., and Evans, D. S.: 1970, Astrophys. J. (Letters) 160, L181.CrossRefGoogle Scholar
Scheuer, P.A.G.: 1962, Australian J. Phys. 15, 333.Google Scholar
Scheuer, P.A.G.: 1965, Monthly Notices Roy. Astron. Soc. 129, 1965.Google Scholar
Sutton, J.: 1966, Ph.D. Thesis, University of Sydney.Google Scholar
Taylor, J. H.: 1966, Nature 210, 1105.Google Scholar
Whitford, A. E.: 1939, Astrophys. J. 89, 472.Google Scholar
Williams, J. D.: 1939, Astrophys. J. 89, 467.Google Scholar