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]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hercules |
Right ascension | 18h 47m 01.23246s[1] |
Declination | +21° 46′ 53.4381″[1] |
Apparent magnitude (V) | 4.34[2] |
Characteristics | |
Spectral type | A5III[3] |
B−V color index | 0.148±0.003[2] |
Astrometry | |
Radial velocity (Rv) | −44.6±2.7[2] km/s |
Proper motion (μ) | RA: +100.536[1] mas/yr Dec.: +116.333[1] mas/yr |
Parallax (π) | 35.3525 ± 0.2680 mas[1] |
Distance | 92.3 ± 0.7 ly (28.3 ± 0.2 pc) |
Absolute magnitude (MV) | 2.04[2] |
Details | |
Mass | 2.40[4] M☉ |
Radius | 1.6[5] R☉ |
Luminosity | 12.84[2] L☉ |
Surface gravity (log g) | 4.35[4] cgs |
Temperature | 8,873±302[4] K |
Metallicity [Fe/H] | 0.33[6] dex |
Rotational velocity (v sin i) | 71[4] km/s |
Age | 559[4] Myr |
Other designations | |
Database references | |
SIMBAD | data |
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]