Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Cepheus |
ο Cep A | |
Right ascension | 23h 18m 37.493s |
Declination | +68° -6′ 41.20″ [1] |
Apparent magnitude (V) | 4.86 [2] |
ο Cep B | |
Right ascension | 23h 18m 37.115s |
Declination | +68° 06′ 38.65″ [3] |
Apparent magnitude (V) | 7.13 [2] |
Characteristics | |
U−B color index | +0.49 [2] |
B−V color index | +0.84 [2] |
R−I color index | +0.45 [2] |
ο Cep A | |
Spectral type | G8III [4] |
ο Cep B | |
Spectral type | F6V [2] |
Astrometry | |
ο Cep A | |
Proper motion (μ) |
RA: 54.88
[1]
mas/
yr Dec.: 10.91 [1] mas/ yr |
Parallax (π) | 15.48 ± 0.55 mas [5] |
Distance | 211 ± 7
ly (65 ± 2 pc) |
Absolute magnitude (MV) | 0.78 [6] |
ο Cep B | |
Proper motion (μ) |
RA: 45.70
[3]
mas/
yr Dec.: 13.19 [3] mas/ yr |
Orbit [4] | |
Period (P) | 1505±40 y |
Semi-major axis (a) | 3.13±0.12 ″ |
Eccentricity (e) | 0.439±0.020 |
Inclination (i) | 16.0±4.0° |
Longitude of the node (Ω) | 4.5±4.5° |
Periastron epoch (T) | B1692 ± 20 |
Argument of periastron (ω) (secondary) | 93.0±20.0° |
Details | |
ο Cep A | |
Mass | 2.35 ± 0.15 [4] M☉ |
Luminosity | 51 [6] L☉ |
Metallicity [Fe/H] | 0.05±0.02 [6] dex |
ο Cep B | |
Mass | 1.29 [4] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Omicron Cephei, Latinized from ο Cephei, is a binary star in the constellation of Cepheus. [5] It consists of a less massive F-type main sequence star in orbit with a more massive G-type giant star. [4] The overall apparent visual magnitude of the system is 4.75. [2]
The pair was first determined to be binary by F. G. W. Struve in 1832. Since then, the secondary has been seen to revolve approximately 45 degrees around the primary. A number of orbits have been computed, the most recent giving a period of approximately 1500 years. [4]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Cepheus |
Right ascension | 23h 18m 37.5s [8] |
Declination | +68° 07′ 26″ [8] |
Apparent magnitude (V) | 12.8 [8] |
Position (relative to A) | |
Epoch of observation | 1912 |
Angular distance | 45.6 ″ [7] |
Position angle | 4° [7] |
Other designations | |
Database references | |
SIMBAD | data |
There is a visual companion, CCDM J23186+6807C, to the binary star. It has an approximate apparent visual magnitude of 12.8 and is located approximately 45 arcseconds away from it. [7] [8]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Cepheus |
ο Cep A | |
Right ascension | 23h 18m 37.493s |
Declination | +68° -6′ 41.20″ [1] |
Apparent magnitude (V) | 4.86 [2] |
ο Cep B | |
Right ascension | 23h 18m 37.115s |
Declination | +68° 06′ 38.65″ [3] |
Apparent magnitude (V) | 7.13 [2] |
Characteristics | |
U−B color index | +0.49 [2] |
B−V color index | +0.84 [2] |
R−I color index | +0.45 [2] |
ο Cep A | |
Spectral type | G8III [4] |
ο Cep B | |
Spectral type | F6V [2] |
Astrometry | |
ο Cep A | |
Proper motion (μ) |
RA: 54.88
[1]
mas/
yr Dec.: 10.91 [1] mas/ yr |
Parallax (π) | 15.48 ± 0.55 mas [5] |
Distance | 211 ± 7
ly (65 ± 2 pc) |
Absolute magnitude (MV) | 0.78 [6] |
ο Cep B | |
Proper motion (μ) |
RA: 45.70
[3]
mas/
yr Dec.: 13.19 [3] mas/ yr |
Orbit [4] | |
Period (P) | 1505±40 y |
Semi-major axis (a) | 3.13±0.12 ″ |
Eccentricity (e) | 0.439±0.020 |
Inclination (i) | 16.0±4.0° |
Longitude of the node (Ω) | 4.5±4.5° |
Periastron epoch (T) | B1692 ± 20 |
Argument of periastron (ω) (secondary) | 93.0±20.0° |
Details | |
ο Cep A | |
Mass | 2.35 ± 0.15 [4] M☉ |
Luminosity | 51 [6] L☉ |
Metallicity [Fe/H] | 0.05±0.02 [6] dex |
ο Cep B | |
Mass | 1.29 [4] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Omicron Cephei, Latinized from ο Cephei, is a binary star in the constellation of Cepheus. [5] It consists of a less massive F-type main sequence star in orbit with a more massive G-type giant star. [4] The overall apparent visual magnitude of the system is 4.75. [2]
The pair was first determined to be binary by F. G. W. Struve in 1832. Since then, the secondary has been seen to revolve approximately 45 degrees around the primary. A number of orbits have been computed, the most recent giving a period of approximately 1500 years. [4]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Cepheus |
Right ascension | 23h 18m 37.5s [8] |
Declination | +68° 07′ 26″ [8] |
Apparent magnitude (V) | 12.8 [8] |
Position (relative to A) | |
Epoch of observation | 1912 |
Angular distance | 45.6 ″ [7] |
Position angle | 4° [7] |
Other designations | |
Database references | |
SIMBAD | data |
There is a visual companion, CCDM J23186+6807C, to the binary star. It has an approximate apparent visual magnitude of 12.8 and is located approximately 45 arcseconds away from it. [7] [8]