Omicron Cephei
Star in the constellation Cepheus
ο Cephei
Observation dataEpoch 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± 0.020Inclination (i) 16.0± 4.0 °Longitude of the node (Ω) 4.5± 4.5 °Periastron epoch (T)B 1692 ± 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 ο Cep, Omicron Cephei, Omicron Cep,
34 Cephei , 34 Cep,
STF 3001AB ,
ADS 16666 AB,
BD +67°1514,
CCDM J23186+6807AB,
GC 32463,
GSC 04478-01361,
HD 219916,
HIP 115088,
HR 8872,
IDS 23145+6734 AB,
PPM 24360,
SAO 20554,
WDS 23186+6807AB.
[5] [7]
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]
Visual companion
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]
References
^ a b c Component 1, HIP 115088 , database entry, The Hipparcos and Tycho Catalogues , 1997, CDS ID I/239 .
^ a b c d e f g HR 8872 , database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50 . Accessed on line November 24, 2008.
^ a b c Component 2, HIP 115088 , database entry, The Hipparcos and Tycho Catalogues , 1997, CDS ID I/239 .
^ a b c d e f Docobo, Jos A. (2003). "Orbit and System Mass for the Visual Binary WDS 23186+6807AB". The Astronomical Journal . 126 (3): 1522–1525. Bibcode :2003AJ....126.1522D . doi :10.1086/377319 . S2CID 54769846 . .
^ a b c "* omi Cep" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved November 24, 2008 .
^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters , 38 (5): 331, arXiv :1108.4971 , Bibcode :2012AstL...38..331A , doi :10.1134/S1063773712050015 , S2CID 119257644 .
^ a b c d e Entry 23186+6807,
The Washington Double Star Catalog ,
United States Naval Observatory . Accessed on line November 24, 2008.
^ a b c d e "UCAC3 317-95637" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved November 24, 2008 .