Magnitude 4.957 Apparent magnitude (V) 4.957 | Constellation Aquila | |
 | ||
People also search for Sigma Aquilae, Chi Aquilae, Nu Aquilae | ||
Kappa Aquilae (κ Aql, κ Aquilae) is the Bayer designation for a star in the equatorial constellation of Aquila. It is a faint star at apparent visual magnitude +4.957, but bright enough to be seen with the naked eye in dark suburban skies. The annual parallax is only 1.94 mas, which equates to a distance of approximately 1,700 light-years (520 parsecs) from Earth (with a 10% margin of error).
The spectrum of Kappa Aquilae matches a stellar classification of B0.5 III, where the luminosity class of III is typically associated with evolved giant stars. This is a huge star with 15.50 times the Sun's mass and 12.5 times the radius of the Sun. Massive stars like this blaze brightly; it is radiating 52,630-fold the Sun's luminosity from its outer atmosphere with a scorching effective temperature of 26,500 K, giving it the intense blue-white glow of a B-type star. It is only 11 million years of age and is spinning rapidly with a projected rotational velocity of 265 km/s.