| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Andromeda[1] |
| HD 225218 A | |
| Right ascension | 00h 04m 36.58441s[2] |
| Declination | +42° 05′ 33.0865″[2] |
| Apparent magnitude (V) | 6.16[3] |
| HD 225218 B | |
| Right ascension | 00h 04m 36.67195s[4] |
| Declination | +42° 05′ 27.8497″[4] |
| Apparent magnitude (V) | 9.65[3] |
| Characteristics | |
| Spectral type | B9III[5] + F0V: |
| U−Bcolor index | 0.14 |
| B−Vcolor index | 0.15 |
| Astrometry | |
| HD 225218 A | |
| Radial velocity (Rv) | −8.0[6] km/s |
| Proper motion (μ) | RA: −10.367±0.266[2]mas/yr Dec.: −14.491±0.222[2]mas/yr |
| Parallax (π) | 3.0041±0.3539 mas[2] |
| Distance | approx. 1,100 ly (approx. 330 pc) |
| HD 225218 B | |
| Proper motion (μ) | RA: −12.314±0.015[4]mas/yr Dec.: −16.129±0.015[4]mas/yr |
| Parallax (π) | 4.4324±0.0208 mas[4] |
| Distance | 736 ± 3 ly (226 ± 1 pc) |
| Orbit[7] | |
| Period (P) | 70.12 yr |
| Semi-major axis (a) | 0.165″ |
| Eccentricity (e) | 0.515 |
| Details | |
| Luminosity | 394[8] L☉ |
| Temperature | 7,611[8] K |
| Rotation | 25[9] |
| Other designations | |
| BD+41 4933,HD 225218,HIP 365,HR 9105,NSV 15012,SAO 36037,WDS J00046+4206 | |
| Database references | |
| SIMBAD | A |
| B | |
HD 225218 is a quadruple star system in the northernconstellation ofAndromeda. The primary component, HD 225218 A, is agiant star with astellar classification of B9III,[5] anapparent magnitude of 6.16,[3] and is a candidateLambda Boötis star.[10] It has a fainter, magnitude 9.65 companion, HD 225218 B, at anangular separation of 5.2″ along aposition angle of 171°.[3] The primary itself has been identified as abinary star system throughinterferometry, with the two components separated by 0.165″. The pair, HD 225218 Aa and Ab, orbit each other with a period of about 70 years and aneccentricity of 0.515.[7] Component B is likewise aspectroscopic binary.[10]
