HD 225218
HD 225218 is a quadruple star system in the northern constellation of Andromeda. The primary component, HD 225218 A, is a giant star with a stellar classification of B9III, an apparent magnitude of 6.16, and is a candidate Lambda Boötis star. It has a fainter, magnitude 9.65 companion, HD 225218 B, at an angular separation of 5.2″ along a position angle of 171°. The primary itself has been identified as a binary star system through interferometry, 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 an eccentricity of 0.515. Component B is likewise a spectroscopic binary.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Andromeda |
| HD 225218 A | |
| Right ascension | 00h 04m 36.58441s |
| Declination | +42° 05′ 33.0865″ |
| Apparent magnitude (V) | 6.16 |
| HD 225218 B | |
| Right ascension | 00h 04m 36.67195s |
| Declination | +42° 05′ 27.8497″ |
| Apparent magnitude (V) | 9.65 |
| Characteristics | |
| Spectral type | B9III + F0V: |
| U−B color index | 0.14 |
| B−V color index | 0.15 |
| Astrometry | |
| HD 225218 A | |
| Radial velocity (Rv) | −8.0 km/s |
| Proper motion (μ) | RA: −10.367±0.266 mas/yr Dec.: −14.491±0.222 mas/yr |
| Parallax (π) | 3.0041 ± 0.3539 mas |
| Distance | approx. 1,100 ly (approx. 330 pc) |
| HD 225218 B | |
| Proper motion (μ) | RA: −12.314±0.015 mas/yr Dec.: −16.129±0.015 mas/yr |
| Parallax (π) | 4.4324 ± 0.0208 mas |
| Distance | 736 ± 3 ly (226 ± 1 pc) |
| Orbit | |
| Period (P) | 70.12 yr |
| Semi-major axis (a) | 0.165″ |
| Eccentricity (e) | 0.515 |
| Details | |
| Luminosity | 394 L☉ |
| Temperature | 7,611 K |
| Rotation | 25 |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Database references | |
| SIMBAD | data |
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