Abstract
TEMPORAL structure down to the millisecond time scale has been observed in the X-ray emission of Cyg X-1 (ref. 1). This has been interpreted as evidence of instabilities in the accretion disk surrounding a black hole2–4, lasting for approximately the orbital period of the infalling matter. We report here observations of modulated optical emission from this source with a period of ∼ 83 ms. The modulated emission was detected in two sets of obserations as transient events lasting ∼ 10 min. This is the first evdence of strong emission at optical wavelengths from the C-ray source in the Cyg X-1-HDE226868 system.
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References
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AURIEMMA, G., CARDINI, D., COSTA, E. et al. Transient short time periodicities in the optical enission from Cyg X-1. Nature 259, 27–29 (1976). https://doi.org/10.1038/259027a0
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DOI: https://doi.org/10.1038/259027a0
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