17 Cygni


17 Cygni is the Flamsteed designation for a binary star system in the northern constellation of Cygnus. It has an apparent visual magnitude of 5.00, so, according to the Bortle scale, it is visible from suburban skies at night. Measurements made with the Hipparcos spacecraft show an annual parallax shift of 0.0478″, which is equivalent to a distance of around from the Sun. It has a relatively high proper motion, traversing the celestial sphere at the rate of /year.
The stellar classification of the primary star is F7 V, which means it is a main sequence star like the Sun. The star has 1.24 times the mass of the Sun and 0.95–1.1 times the Sun's radius. It is some 2.8 billion years old and shines with 3.66 times the Sun's luminosity. The effective temperature of the stellar atmosphere is 6,455 K, giving it the yellow-white hued glow of an F-type star.
At an angular separation of 791.40 arcseconds is a proper motion companion with a classification of M0.4, indicating this is a red dwarf star. At the estimated distance of the pair, this is equal to a projected separation of 16,320 AU. Although the CCDM lists four other companions, these are not associated with the pair.