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James C. Kemp was born in Detroit, Michigan on 9 February 1927, and died in Eugene, Oregon, on 29 March 1988. He went to high school in Mexico City and did undergraduate studies at the University of Michigan and University of California at Berkeley. Kemp was an active observational astronomer, having migrated from earlier interests in Slavic languages, in which he majored, electrical engineering, and physics. He obtained a PhD in electrical engineering at Berkeley in 1960 and did post-doctoral work there with Erwin Hahn on spin resonance. He went to the University of Oregon in 1961 and conducted research in magneto-optics, developing, in the process, a piezo-optical birefringence modulator to measure circular polarization. The modulator is described by Tinbergen (1996).
Kemp explored new areas as he measured magnetic fields in the sunspots with polarized infrared light, and developed polarimeters and photometers to study the behavior of such astronomical sources as white dwarfs, the relativistic jets of binary SS 433, the x-ray binary Cyg X-1, and the bright eclipsing binaries Algol and e Aurigae on the 61- and, later, 81-cm telescope at the Pine Mountain Observatory, of which Kemp was director until his death from cancer. His measurement of circularly polarization in the continuum light of the white dwarf GJ 742 (Grw +70 ∘ 8247, Kemp et al. 1970b) was an important discovery, and through his study of Algol (Kemp et al. 1983; Wilson & Liou 1993), he appears to have been the first to discover the limb polarization in eclipsing binaries predicted by Chandrasekhar (1946ab).
Although it has taken twenty years for the BAAS to publish his obituary notice, it is somewhat appropriate that his former student, Gary Henson, who provided much of the background for this article, is involved with a polarimetry team to observe and analyze data from e Aurigae, as it approaches ingress of the next primary minimum beginning summer, 2009. The author acknowledges with gratitude the additional assistance of T. A. Clark and R. E. Wilson in preparing this article.
Representative Publications and References:
Chandrasekhar, S. 1946a, ApJ, 103, 361.
Chandrasekhar, S. 1946b, ApJ, 104, 110.
Donnelly, R. J. 1989, "James C. Kemp," Physics Today, 42, 94.
Henson, G. D. 2008, private communication.
Kemp, J. C., 1969, "Piezo-optical birefringence modulators: new use for a long-known effect," J. Opt. Soc. Am., 59, 950.
Kemp, J. C. and Henson, G. D., 1983, "Broad-band circular polarization of sunspots, 0.27-4.5 microns," ApJ, 266, L69.
Kemp, J. C., Macek, J. H., Nehring, F. W. 1984, "Induced atomic orientation, an efficient mechanism for magnetic circular polarization," ApJ, 278, 863.
Kemp, J. C., Swedlund, J. B., and Evans, B. D. 1970a, "Magnetoemission from incandescent sources," Phys. Rev. Let., 24, 1211.
Kemp. J. C., Swedlund, J. B., Landstreet, J. D., and Angel, J. R. P. 1970b, "Discovery of Circularly Polarized Light from a White Dwarf," ApJL, 161, L77.
Kemp, J. C., Henson, G. D., Steiner, C. T., Powell, E. R. 1987, "The optical polarization of the Sun measured at a sensitivity of parts in ten million," Nature, 326, 270.
Kemp, J. C., Henson, G. D., Barbour, M. S., Kraus, D. J., and Collins, G. W. 1983, "Discovery of Eclipse Polarization in Algol," ApJ, 273, L85.
Kemp, J. C., Henson, G. D., Kraus, D. J., Beardsley, I. S., Carroll, L. C., Ake, T. B., Simon, T., and Collins, G. W. 1986, "Epsilon Aurigae: Polarization, Light Curves, and Geometry of the 1982-1984 Eclipse," ApJL, 300, L11.
Kemp, J. C., Henson, G. D., Kraus, D. J., Carroll, L. C., Beardsley, I. S., Takagishi, K., Jugaku, J., Matsuoka, M., Leibowitz, E. M., Mazeh, T., and Mendelson, H. 1986, "SS 433: A 6 Year Photometric Record," ApJ, 305, 805.
Tinbergen, J. 1996, Astronomical Polarimetry, (Cambridge: Cambridge University Press), pp. 95-96.
Wilson, R. E., and Liou, J.-C. 1993, ApJ, 413, 670.
Obituary written by: E. F. Milone (University of Calgary)
BAAS Citation: BAAS, 2009, 41, 569
SAO/NASA ADS Bibcode: 2009BAAS...41..569M