Blue band photometry of Cygnus X-1 during 1973.
HDE 226868 (= Cygnus X-I) has been monitored in blue light during 1973. The 1973 light curve is of improved quality compared with the 1972 results. It does not confirm the evidence for an increasing amplitude found during 1972. The star was consistently brighter in 1973 by I per cent. The trailing side of the Bo Ib star seems to be a site of photometric variability.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 1974