| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hercules |
| Right ascension | 18h 05m 49.682s[2] |
| Declination | +21° 26′ 45.39″[2] |
| Apparent magnitude (V) | 6.94[citation needed] |
| Characteristics | |
| HD 165590A | |
| Evolutionary stage | main sequence |
| Spectral type | G1V+K6V[3] |
| HD 165590B | |
| Evolutionary stage | main sequence |
| Spectral type | G5V[3] |
| Astrometry | |
| ADS 11060AB | |
| Proper motion (μ) | RA: −3.9±0.5mas/yr[4] Dec.: −51.4±0.7mas/yr[4] |
| Parallax (π) | 26.51±1.35 mas[5] |
| Distance | 123 ± 6 ly (38 ± 2 pc) |
| ADS 11060C | |
| Proper motion (μ) | RA: −27.515±0.014 mas/yr Dec.: −39.93±0.02 mas/yr |
| Parallax (π) | 24.6940 ± 0.0225 mas[6] |
| Distance | 132.1 ± 0.1 ly (40.50 ± 0.04 pc) |
| Details[3] | |
| HD 165590Aa | |
| Mass | 1.09±0.19 M☉ |
| Radius | 0.90 R☉ |
| Surface gravity (log g) | 4.56 cgs |
| Temperature | 5,915 K |
| Metallicity [Fe/H] | −0.13 dex |
| Age | 100 Myr |
| HD 165590Ab | |
| Mass | 0.63±0.15 M☉ |
| Radius | 0.58 R☉ |
| Surface gravity (log g) | 4.71 cgs |
| Temperature | 4,055 K |
| HD 165590B | |
| Radius | 0.91±0.09 R☉ |
| Temperature | 5,590±300 K |
| Age | 100 Myr |
| Other designations | |
| ADS 11060, CSI+21 3302 1, GSC 01566-00747, HIP 88637,2MASS J18054972+2126453, BD+21 3302, SBC9 1024, V772 Her, Gaia DR2 4576326312901654272 | |
| HD 165590A: TYC 1566-747-1, SBC9 1023, CSI+21 3302 6, ADS 11060A | |
| HD 165590B: TYC 1566-747-2, CSI+21 3302 7, ADS 11060B | |
| Database references | |
| SIMBAD | data |
HD 165590 is a quintuple system dominated by the binaryAlgol variable star known asV772 Herculis. The system lies in the constellation ofHercules about123 light years from the Sun, and is suspected to be a part of thePleiades moving group.[5]
The primary star is aneclipsing binary ADS 11060A composed of G1 and K6 young main-sequence stars with strongstarspot activity.[3] A radio flare from the star V772 Her was detected in 2011.[7] The period of the components of the primary, ADS 11060Aa and ADS 11060Ab, is 0.87950 days.[5]
Amain-sequence companion star ADS 11060B of spectral type G5 at a separation of 0.491 arcseconds,[8] is orbiting the primary with a period of 20.08 years.[5]
Also, there is a suspected companion binary star ADS 11060C (Gaia EDR3 4576326312901650560)[6] at a projected separation of 29 arcseconds (1200AU) from ADS 11060AB. ADS 11060C is composed of K7 and M0 main-sequence stars, orbiting each other with a period of 25.7631 days without eclipses. The binary is aBY Draconis variable[9] with thevariable star designation V885 Herculis.
The planetary orbits in the habitable zones in the system ADS 11060AB are unstable due to the gravitational influence of the stellar companions.[10]
