15_Cygni
15 Cygni
Star in the constellation Cygnus
15 Cygni is a single[7] star in the northern constellation Cygnus. With an apparent visual magnitude of 4.90,[2] it is a faint star but visible to the naked eye. The distance to 15 Cygni can be estimated from its annual parallax shift of 11.0 mas,[1] which yields a separation of some 296 light years. It is moving closer to the Sun with a heliocentric radial velocity of −23.6 km/s.[4]
This is an aging giant star with a stellar classification of G8 III,[2] having consumed the hydrogen at its core and evolved off the main sequence. It is a red clump giant,[8] which means it is generating energy via helium fusion at its core. The star is 1.50 billion years old with 2.3 times the mass of the Sun,[3] and has expanded to 12 times the Sun's radius.[4] It is radiating 93 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,920 K.[3]