| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Draco |
| Right ascension | 18h 53m 13.55478s[1] |
| Declination | +50° 42′ 59.1821″[1] |
| Apparent magnitude (V) | 4.92[2] |
| Characteristics | |
| Spectral type | G7 IIIa Fe−1[3] |
| U−Bcolor index | 0.57[4] |
| B−Vcolor index | 0.90[2] |
| Astrometry | |
| Radial velocity (Rv) | +8.5[2] km/s |
| Proper motion (μ) | RA: 0.938mas/yr Dec.: −24.171mas/yr |
| Parallax (π) | 10.7890±0.2187 mas[1] |
| Distance | 302 ± 6 ly (93 ± 2 pc) |
| Absolute magnitude (MV) | −0.78[5] |
| Orbit[4] | |
| Period (P) | 972.84±0.35 d |
| Eccentricity (e) | 0.342±0.006 |
| Periastronepoch (T) | 53,678.2±2.4 |
| Argument of periastron (ω) (secondary) | 190.0±1.1° |
| Semi-amplitude (K1) (primary) | 5.83±0.04 km/s |
| Details | |
| Mass | 3.27[2] M☉ |
| Radius | 13[6] R☉ |
| Luminosity | 219[2] L☉ |
| Surface gravity (log g) | 2.85±0.15[7] cgs |
| Temperature | 5,024±74[2] K |
| Metallicity [Fe/H] | −0.07±0.07[7] dex |
| Rotational velocity (v sin i) | 2.3[8] km/s |
| Age | 320[2] Myr |
| Other designations | |
| BD+50° 2686,HD 175535,HIP 92689,HR 7137,SAO 31241[9] | |
| Database references | |
| SIMBAD | data |
HD 175535 is abinary star system in the northerncircumpolar constellation ofDraco. It has anapparent visual magnitude of 4.92,[2] which is bright enough to be faintly visible to the naked eye. The system is located about 302 light years away, as determined from its annualparallax shift of10.8 mas.[1] It is moving further from the Earth with a heliocentricradial velocity of +8.5 km/s.[2]
The binary nature of this system was announced byW. W. Campbell of theLick Observatory in 1911. It is a single-linedspectroscopic binary with anorbital period of 2.66 years (972.84 d) and aneccentricity of 0.342. Thea sini value for the visible component is73.4±0.6 Gm, wherea is thesemimajor axis andi is the (unknown)orbital inclination.[4] This indicates that the actual semimajor axis is larger than 0.49 AU.[10]
The visible component appears to be anevolvedgiant star with astellar classification ofG7 IIIa Fe−1,[3] where the suffix notation indicates an underabundance of iron in theatmosphere. It is 320[2] million years old with 3.27[2] times themass of the Sun and about 13[6] times theSun's radius. The star is radiating 219[2] times theSun's luminosity from its enlargedphotosphere at aneffective temperature of 5,024 K.[2]
