Pi Cephei
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This infobox, "Template:Starbox begin", is from Wikipedia. The list of its authors can be seen in its edit history page. The data in this infobox may not agree or state what Wikipedia states. |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus |
| Right ascension | 23h 07m 53.854s[1] |
| Declination | +75° 23′ 15.00″[1] |
| Apparent magnitude (V) | 4.419[2] 4.61[3] + 6.75[4]) |
| Characteristics | |
| Spectral type | G7III[5] / F5V[5] / A7V-A9V[6] |
| U−B color index | -0.46 |
| B−V color index | 0.8 |
| Astrometry | |
| Radial velocity (Rv) | -18.6 ± 0.9 km/s |
| Proper motion (μ) | RA: 6.81 ± 1.05[1] mas/yr Dec.: -34.06 ± 0.88[1] mas/yr |
| Parallax (π) | 13.8 ± 0.41[6] mas |
| Distance | 236 ± 7 ly (72 ± 2 pc) |
| Absolute magnitude (MV) | 0.24 |
| Orbit[5] | |
| Primary | π Cep Aa |
| Companion | π Cep Ab |
| Period (P) | 556.72 ± 0.05 d |
| Semi-major axis (a) | 39.0 ± 3.9 mas[6] |
| Eccentricity (e) | 0.297 ± 0.006 |
| Inclination (i) | 99.0 ± 2.5[6]° |
| Longitude of the node (Ω) | 109.2 ± 3.5[6]° |
| Periastron epoch (T) | 2,439,172.9 ± 1.6 |
| Argument of periastron (ω) (secondary) | 7.6 ± 1.2° |
| Semi-amplitude (K1) (primary) | 24.18 ± 0.15 km/s |
| Orbit[7] | |
| Primary | π Cephei A (Aa + Ab) |
| Companion | π Cephei B |
| Period (P) | 162.8 ± 2.8 yr |
| Semi-major axis (a) | 0.810 ± 0.050″ |
| Eccentricity (e) | 0.5968 ± 0.0067 |
| Inclination (i) | 30.0 ± 3.0° |
| Longitude of the node (Ω) | 90.3 ± 4.9° |
| Periastron epoch (T) | B 1934.573 ± 0.35 |
| Argument of periastron (ω) (secondary) | 90.0 ± 4.4° |
| Details[6] | |
| π Cep Aa | |
| Mass | 3.63 ± 0.53 M☉ |
| Surface gravity (log g) | 3.05±0.11[8] cgs |
| Temperature | 5,226±92[8] K |
| Metallicity [Fe/H] | 0.29±0.05[8] dex |
| Age | 100[8] Myr |
| π Cep Ab | |
| Mass | 3.27 ± 0.48 M☉ |
| π Cep B | |
| Mass | 1.93 ± 0.23 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Pi Cephei (π Cephei) is a trinary star located in the constellation Cepheus.[6] With a combined apparent magnitude of about 4.4,[2] the system is faintly visible to the naked eye. The inner pair of stars orbits in 1.5 years while the outer companion completes one orbit in about 160 years.[6]
Stellar system[edit]
Pi Cephei was found to have a visual companion star by Otto Wilhelm von Struve in 1843.[6] That the primary is itself a spectroscopic binary was first noticed by William Wallace Campbell in 1901 using photographic plates taken at Lick Observatory.[10]
References[edit]
- ↑ 1.0 1.1 1.2 1.3 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:10.1051/0004-6361:20078357. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL. Vizier catalog entry
- ↑ 2.0 2.1 Hauck, B.; Mermilliod, M. (1998). "Uvbybeta photoelectric photometric catalogue". Astronomy and Astrophysics Supplement 129 (3): 431–433. Bibcode 1998A&AS..129..431H. doi:10.1051/aas:1998195. http://aas.aanda.org/articles/aas/full/1998/09/ds1467/ds1467.html.Vizier catalog entry
- ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27. Bibcode 2000A&A...355L..27H.
- ↑ Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (2002). "The Tycho double star catalogue". Astronomy and Astrophysics 384: 180–189. Bibcode 2002A&A...384..180F. doi:10.1051/0004-6361:20011822.
- ↑ 5.0 5.1 5.2 Scarfe, C. D. et al. (1983). "Revised orbits for 105 Herculis and Pi Cephei A and a model for the Pi Cephei system". Monthly Notices of the Royal Astronomical Society 203: 103–116. Bibcode 1983MNRAS.203..103S. doi:10.1093/mnras/203.1.103. http://articles.adsabs.harvard.edu/full/1983MNRAS.203..103S.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 Gatewood, George et al. (2001). "Hipparcos and MAP Studies of the Triple Star π Cephei". The Astrophysical Journal 549 (2): 1145–1150. Bibcode 2001ApJ...549.1145G. doi:10.1086/319458. http://iopscience.iop.org/0004-637X/549/2/1145/fulltext/.
- ↑ Lua error in Module:Citation/CS1 at line 379: attempt to call method 'match' (a nil value).
- ↑ 8.0 8.1 8.2 8.3 Feuillet, Diane K.; Bovy, Jo; Holtzman, Jon; Girardi, Léo; MacDonald, Nick; Majewski, Steven R.; Nidever, David L. (2016). "Determining Ages of APOGEE Giants with Known Distances". The Astrophysical Journal 817 (1): 40. Bibcode 2016ApJ...817...40F.
- ↑ Lua error in Module:Citation/CS1 at line 379: attempt to call method 'match' (a nil value).
- ↑ Campbell, William Wallace (1901). "Some recent results secured with the Mills spectrograph". Lick Observatory Bulletin 1 (4): 22–25. Bibcode 1901LicOB...1...22C. doi:10.5479/ADS/bib/1901LicOB.1.22C. http://articles.adsabs.harvard.edu/full/1901LicOB...1...22C.
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