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Evidence for an approx. 300 day period in Cygnus X-1

Journal Article · · Astrophys. J.; (United States)
DOI:https://doi.org/10.1086/161114· OSTI ID:5471693
We present the time history of X-ray emission from Cyg X-1 over an 11 year period, with 10 day resolution. The data were obtained by experiments on the Vela 5B (1969--1979) and Ariel 5 (1974--1980) satellites. Cyg X-1 varies by approx.25% with a 294 +- 4 day period. This modulation is apparently unrelated to the known transitions between the source high and low states. Flux minima occur at 1974.05+nP. The observed period is within the possible range for the precession period of an accretion disk, or of the companion star HDE 226868, in the Cyg X-1 system.
Research Organization:
Earth and Space Sciences Division, Los Alamos National Laboratory
OSTI ID:
5471693
Journal Information:
Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 270:1; ISSN ASJOA
Country of Publication:
United States
Language:
English

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