Three-color photometry of HDE 226868: The optical counterpart of cygnus X-1

Journal Article · Sat May 01 04:00:00 EDT 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154341· OSTI ID:7347443

Lester, D F; Nolt, I G; Stearns, S A; Straton, P; Radostitz, J V

The results of UBV photoelectric observations of HDE 226868 (Cyg X-1) obtained on fifty nights during 1974 are presented. These observations show a light curve with the following characteristics: two unequal light maxima and minima during the 5/sup d/.6 orbital period which exhibit a peak-to-peak magnitude change of approx.0.07 mag in all colors;a small phase-dependent color variation which results in a reddening in both color indices of approx.0.003 mag at times of light minima; erratic light variability on a general time scale of days with an amplitude of +- 0.01 to 0.02 mag and no apparent color dependence. (AIP)

• Research Organization: Department of Physics, University of Oregon, Eugene
• OSTI ID: 7347443
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 205:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640103 -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
BLACK HOLES
COLOR
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
GIANT STARS
MASS
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHOTOMETRY
PHYSICAL PROPERTIES
STARS
SUPERGIANT STARS