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Non-solar gamma and X-ray astronomy: optical observations∗: (Invited discourse)

Published online by Cambridge University Press:  14 August 2015

Hugh M. Johnson
Hugh M. Johnson*
Affiliation:
Lockheed Missiles and Space Company, Palo Alto, Calif., U.S.A., and Cerro Tololo Inter-American Observatory‡

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An optical astronomer enters this field only by courtesy of those X-ray astronomers who pay some attention to accurate positional measurements of X-ray sources. So my first and last words are to ask X-ray observers to give more time to establishing positions of X-ray sources. It appears that in fact most effort has been spent on spectral measurements of X-rays, and this has led just to the classification of sources according to either of two mechanisms for the production of the continuum. In one or two early instances the extrapolated X-ray spectrum has been useful for predicting the brightness of the optical counterpart to be found. A typical uncertainty of making optical identification is that of Vel XR-1 for which Gursky et al. (1968) have given a position with an error box of 3 square degrees. One candidate I can suggest for this is CU Vel, the only variable star of the 1958 General Catalogue of Variable Stars inside the error box. It is interesting because it is assigned to the U Gem class with a range of photographic magnitudes from 10.7 to 15.5. The stellar spectrum has not been observed.

Type
Research Article
Information
Symposium - International Astronomical Union , Volume 37: Non-Solar X- and Gamma-Ray Astronomy , 1970 , pp. 151 - 161
Copyright
Copyright © Reidel 1970 

References

Ables, J. G.: 1969, Astrophys. J. (Letters) 155, L27.Google Scholar
Andrew, B. H. and Purton, C. R.: 1968, Nature 218, 855.Google Scholar
Bertiau, F. C.: 1958, Astrophys. J. 128, 533.Google Scholar
Blaauw, A.: 1961, Bull. Astron. Inst. Netherl. 15, 265.Google Scholar
Blanco, V., Kunkel, W., Hiltner, W. A., Chodil, G., Mark, H., Rodrigues, R., Seward, F., and Swift, C. D.: 1968a, Astrophys. J. (Letters) 152, L135.Google Scholar
Blanco, V., Kunkel, W., and Hiltner, W. A.: 1968b, Astrophys. J. (Letters) 152, L137.CrossRefGoogle Scholar
Eggen, O. J., Freeman, K. C., and Sandage, A.: 1968, Astrophys. J. (Letters) 154, L27.Google Scholar
Freeman, K. C., Rodgers, A. W., and Lyngå, G.: 1968, Nature 219, 251.CrossRefGoogle Scholar
Genderen, A. M. van: 1969, Astron. and Astrophys. 2, 6.Google Scholar
Gursky, H., Kellogg, E. M., and Gorenstein, P.: 1968, Astrophys. J. (Letters) 154, L71.Google Scholar
Johnson, H. M.: 1966, Astrophys. J. 144, 635.Google Scholar
Johnson, H. M.: 1968a, Astrophys. J. 154, 1139.Google Scholar
Johnson, H. M.: 1968b, Canadian J. Phys. 46, S481.Google Scholar
Johnson, H. M. and Golson, J. C.: 1968a, Astrophys. J. 153, 307.CrossRefGoogle Scholar
Johnson, H. M. and Golson, J. C.: 1968b, Astrophys. J. (Letters) 154, L77.Google Scholar
Johnson, H. M. and Stephenson, C. B.: 1966, Astrophys. J. 146, 602.Google Scholar
Luyten, W. J.: 1966, I.A.U. Circ. No. 1980.Google Scholar
Lynds, B. T.: 1962, Astrophys. J. Suppl. 7, 1.Google Scholar
Lynds, B. T.: 1965, Astrophys. J. Suppl. 12, 163.Google Scholar
Mark, H., Price, R. E., Rodrigues, R., Seward, F. D., Swift, C. D., and Hiltner, W. A.: 1969, Astrophys. J. (Letters) 156, L67.Google Scholar
Neugebauer, G., Oke, J. B., Becklin, E., and Garmire, G.: 1969, Astrophys. J. 155, 1.Google Scholar
Pelling, R. M., Matteson, J. L., Peterson, L. E., Johnson, H. M., and Golson, J. C.: 1969, 129th AAS meeting (Honolulu).Google Scholar
Riegler, G. R. and Ramaty, R.: 1969, Astrophys. Letters 4, 27.Google Scholar
Sofia, S., Eichhorn, H., and Gatewood, G.: 1969, Astron J. 74, 20.Google Scholar
Wallerstein, G.: 1967, Astrophys. Letters 1, 31.Google Scholar