111_Herculis
111 Herculis
Star in the constellation Hercules
111 Herculis is a suspected astrometric binary[8] star system located 92 light years from the Sun in the northern constellation Hercules. It is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 4.34.[2] The system is moving nearer to the Earth with a heliocentric radial velocity of −45 km/s, and may come as close as 37 light-years in 537,000 years.[2]
According to Cowley et al. (1969), the visible component has a stellar classification of A5III,[3] matching an A-type giant star. Abt and Morrell (1995) listed it as type A3IV, suggesting it is instead a less evolved subgiant star.[9] The interferometry-measured angular diameter of the primary component is 0.52±0.02 mas,[10] which, at its estimated distance, equates to a physical radius of roughly 1.6 times the radius of the Sun.[5] The star is estimated to be 559[4] million years old with 2.40[4] times the mass of the Sun and is spinning with a projected rotational velocity of 71 km/s.[4] It is radiating 13 times the Sun's luminosity from its photosphere at an effective temperature of 8,873 K.[4]