HD 188753
HD 188753 is a hierarchical triple star system approximately 151 light-years away in the constellation of Cygnus, the Swan. In 2005, an extrasolar planet was announced to be orbiting the primary star (designated HD 188753 A) in the system. Follow-up measurements by an independent group in 2007 did not confirm the planet's existence.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 54m 58.37177s |
| Declination | +41° 52′ 17.5298″ |
| Apparent magnitude (V) | +7.43 |
| Characteristics | |
| Spectral type | A: G8V |
| U−B color index | +0.42 |
| B−V color index | +0.79 |
| Astrometry | |
| Radial velocity (Rv) | -23.5 km/s |
| Proper motion (μ) | RA: -51.32 mas/yr Dec.: 286.57 mas/yr |
| Parallax (π) | 21.63 ± 0.65 mas |
| Distance | 151 ± 5 ly (46 ± 1 pc) |
| Absolute magnitude (MV) | 4.17 |
| Orbit | |
| Primary | HD 188753 A |
| Companion | HD 188753 BC |
| Period (P) | 25.63 yr |
| Semi-major axis (a) | 0.2587" (11.8 au) |
| Eccentricity (e) | 0.502 |
| Inclination (i) | 31.1° |
| Longitude of the node (Ω) | 45.7° |
| Periastron epoch (T) | 1988.1 |
| Argument of periastron (ω) (secondary) | 233.3° |
| Semi-amplitude (K1) (primary) | 4.8 km/s |
| Semi-amplitude (K2) (secondary) | 3.4 km/s |
| Details | |
| Mass | A: 1.06 ± 0.07 M☉ B: 0.96 ± 0.05 M☉ C: 0.67 ± 0.05 M☉ |
| Temperature | A: 5,750 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
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