HR 9038
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 23h 52m 25.31799s |
| Declination | +75° 32′ 40.5141″ |
| Apparent magnitude (V) | 6.40 (6.93 / 7.33) / 11.4 |
| Characteristics | |
| Spectral type | K3 V + K3 V + M2 |
| U−B color index | 0.70 |
| B−V color index | 0.98 |
| R−I color index | 0.5 |
| Astrometry | |
| Radial velocity (Rv) | +4.60 km/s |
| Proper motion (μ) | RA: 341.01 mas/yr Dec.: 41.50 mas/yr |
| Parallax (π) | 91.82±0.30 mas |
| Distance | 35.5 ± 0.1 ly (10.89 ± 0.04 pc) |
| Absolute magnitude (MV) | 6.77 / 7.16 / ? |
| Absolute bolometric magnitude (Mbol) | 6.34 / 6.62 / ? |
| Orbit | |
| Primary | HR 9038 A |
| Companion | HR 9038 B |
| Period (P) | 290.0 yr |
| Semi-major axis (a) | 4.14″ |
| Eccentricity (e) | 0.55 |
| Inclination (i) | 49.58° |
| Longitude of the node (Ω) | 93.91° |
| Periastron epoch (T) | 2015.0 |
| Argument of periastron (ω) (secondary) | 134.14° |
| Orbit | |
| Primary | HR 9038 Aa |
| Companion | HR 9038 Ab |
| Period (P) | 7.7531 d |
| Eccentricity (e) | 0.0 |
| Inclination (i) | ~60° |
| Periastron epoch (T) | 2420001.264 |
| Argument of periastron (ω) (secondary) | 0.0° |
| Semi-amplitude (K1) (primary) | 39.9 km/s |
| Semi-amplitude (K2) (secondary) | 49.7 km/s |
| Details | |
| HR 9038 Aa | |
| Mass | 0.70 M☉ |
| Radius | 0.69 R☉ |
| Surface gravity (log g) | 4.60 cgs |
| Temperature | 4820 K |
| Metallicity [Fe/H] | -0.29 dex |
| HR 9038 Ab | |
| Mass | 0.67 M☉ |
| Radius | 0.66 R☉ |
| Surface gravity (log g) | 4.62 cgs |
| Temperature | 4620 K |
| Metallicity [Fe/H] | -0.29 dex |
| Other designations | |
| BD+74° 1047, GJ 909, WDS J23524+7533 | |
| HR 9038 A: HD 223778, HIP 117712, HR 9038, SAO 10879 | |
| Database references | |
| SIMBAD | A |
| B | |
HR 9038 is a triple star system located thirty-five light-years away, in the constellation Cepheus. Component A is a spectroscopic binary system with an orbital period of 7.753 days and a combined stellar classification of K3 V. Component B is a red dwarf star that orbits the primary pair every 290 years.