HD 225218
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 04m 36.58707s[1] |
| Declination | +42° 05′ 33.1118″[1] |
| Apparent magnitude (V) | 6.133 (6.16 + 9.65)[2] |
| Characteristics | |
| Spectral type | B9III[3] + F0V: |
| U−B color index | 0.14 |
| B−V color index | 0.15 |
| Astrometry | |
| Radial velocity (Rv) | −8.0[4] km/s |
| Proper motion (μ) | RA: −11.35±0.42[1] mas/yr Dec.: −12.64±0.36[1] mas/yr |
| Parallax (π) | 2.59 ± 0.56[1] mas |
| Distance | approx. 1,300 ly (approx. 390 pc) |
| Orbit[5] | |
| Period (P) | 70.12 yr |
| Semi-major axis (a) | 0.165" |
| Eccentricity (e) | 0.515 |
| Details | |
| Luminosity | 394[6] L☉ |
| Temperature | 7,611[6] K |
| Rotation | 25[7] |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Database references | |
| SIMBAD | data |
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,[3] an apparent magnitude of 6.16,[2] and is a candidate Lambda Boötis star.[8] It has a fainter, magnitude 9.65 companion, HD 225218 B, at an angular separation of 5.2″ along a position angle of 171°.[2] 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.[5] Component B is likewise a spectroscopic binary.[8]
References
- 1 2 3 4 5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752
, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357Vizier catalog entry - 1 2 3 Mason, Brian D.; et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466−3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
- 1 2 Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819
- ↑ Wilson, R. E. (1953), General Catalogue of Stellar Radial Velocities, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W
- 1 2 Malkov, O. Yu.; et al. (2012), "Dynamical Masses of a Selected Sample of Orbital Binaries", Astronomy & Astrophysics, 546: 5, Bibcode:2012A&A...546A..69M, doi:10.1051/0004-6361/201219774, A69
- 1 2 McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x
- ↑ Abt, Helmut A.; et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590
- 1 2 Faraggiana, Rosanna; Bonifacio, Piercarlo (September 1999), "How many lambda Bootis stars are binaries?", Astronomy and Astrophysics, 349: 521−531, arXiv:astro-ph/9906009, Bibcode:1999A&A...349..521F
External links
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