Abstract
THE sudden appearance1,2 of a faint radio source inside the probable position region for the X-ray source Cyg X-1 was associated with major changes in the X-ray emission observed3 during the period February–May 1971. This coincidence established a probable association with the X-ray source. The accurate position of the radio source led to an identification2,4 with the bright, blue star HDE226868. Subsequent optical investigations have established5,6 this object to be a binary system with a massive, invisible component that may be a black hole.
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References
Hjellming, R. M., and Wade, C. M., Astrophys. J. Lett., 168, L21 (1971).
Braes, L. L. E., and Miley, G. K., Nature, 232, 246 (1971).
Tananbaum, H., Gursky, H., Kellog, E., Giacconi, R., and Jones, C., Astrophys. J. Lett., 177, L5 (1972).
Wade, C. M., and Hjellming, R. M., Nature, 235, 271 (1972).
Webster, B., and Murdin, P., Nature, 235, 37 (1972).
Bolton, C. T., Nature, 235, 271 (1972).
Gursky, H., et al., IAU Circ. no. 2778 (1975).
Hjellming, R. M., Astrophsy. J. Lett., 182, L29 (1973).
Braes, L. L. E., and Miley, G. K., Nature phys. Sci., 235, 147 (1972).
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HJELLMING, R., GIBSON, D. & OWEN, F. Another major change in the radio source associated with Cyg X-1. Nature 256, 111–112 (1975). https://doi.org/10.1038/256111a0
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DOI: https://doi.org/10.1038/256111a0
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