Pi Cephei
From Infogalactic: the planetary knowledge core
| 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] |
| Characteristics | |
| Spectral type | G7III[3] / F5V[3] / A7V-A9V[4] |
| U−B color index | -0.46 |
| B−V color index | 0.8 |
| Variable type | None |
| 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[4] mas |
| Distance | 236 ± 7 ly (72 ± 2 pc) |
| Absolute magnitude (MV) | 0.24 |
| Orbit[3] | |
| Primary | Pi Cephei Aa |
| Companion | Pi Cephei Ab |
| Period (P) | 556.72 ± 0.05 days |
| Semi-major axis (a) | 39.0 ± 3.9 Mas[4] |
| Eccentricity (e) | 0.297 ± 0.006 |
| Inclination (i) | 99.0 ± 2.5[4]° |
| Longitude of the node (Ω) | 109.2 ± 3.5[4]° |
| 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[5] | |
| Primary | Pi Cephei A (Aa + Ab) |
| Companion | Pi Cephei B |
| Period (P) | 160 yr |
| Semi-major axis (a) | 0.84" |
| Eccentricity (e) | 0.58 |
| Inclination (i) | 28.4° |
| Longitude of the node (Ω) | 63.5° |
| Periastron epoch (T) | 1933.95 |
| Argument of periastron (ω) (secondary) |
115.3° |
| Details | |
| Mass | 6.88±0.69 M☉ |
| Radius | ? R☉ |
| Luminosity | ? L☉ |
| Temperature | ? K |
| Metallicity | ? |
| Rotation | ? |
| Age | ? years |
| Other designations | |
Pi Cephei (π Cep) is a trinary star located in the constellation Cepheus.[4] The inner pair of stars orbits in 1.5 years while the outer companion completes one orbit in about 160 years.[4]
Stellar system
Pi Cephei was found to have a visual companion star by Otto Wilhelm von Struve in 1843.[4] That the primary is itself a spectroscopic binary was first noticed by William Wallace Campbell in 1901 using photographic plates taken at Lick Observatory.[7]
References
- ↑ 1.0 1.1 1.2 1.3 Lua error in package.lua at line 80: module 'strict' not found. Vizier catalog entry
- ↑ Lua error in package.lua at line 80: module 'strict' not found.Vizier catalog entry
- ↑ 3.0 3.1 3.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
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