32 Cygni
32 Cygni (32 Cyg, Omicron2 Cyg, ο2 Cyg) is the Flamsteed designation for a binary star system in the Cygnus constellation. It is a 4th magnitude star, which can be seen with the naked eye under suitably dark skies. Parallax measurements give an estimated distance of 1,100 light-years (320 parsecs) from the Earth. However, Schröder et al. (2007) suggest the actual value, after correcting for Malmquist bias, may be closer to 1,174 light-years (360 parsecs).
The primary component in this system, 32 Cygni A, has a stellar classification of K4–5 Ib, indicating that it is a lower luminosity supergiant star. Its effective temperature of 3,840 K lies in the range for K-type stars, giving it an orange hue. This star has more four than times the mass of the Sun and the outer envelope has expanded to about 184 times the Sun's radius. It is radiating 6,600 times the luminosity of the Sun.
The companion star, 32 Cygni B, is smaller than the primary, with four times the Sun's mass and three times the Sun's radius. It has a much higher effective temperature of 16,200 K and is radiating over 300 times the Sun's luminosity. This star has the blue-white hue of a B-type star, with a stellar classification of B6–7 IV–V. The luminosity class 'IV–V' fits a star that has nearly exhausted the hydrogen at its core and begun to evolve off the main sequence to become a subgiant star.
Omicron Cygni
The Bayer designation Omicron Cygni (ο Cyg / ο Cygni) is shared by two star systems, in the constellation Cygnus:
31 Cygni
31 Cygni, also known as Omicron1 Cygni or V695 Cygni, is a star in the constellation Cygnus. An Algol-type eclipsing binary, it ranges between magnitudes 3.73 and 3.89 over a period of ten years; the component stars are an orange supergiant of spectrial type K4Iab and a blue-white star likely to be evolving off the main sequence with a spectral type of B4IV-V.
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